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MONTHYEARPMNS20210441, Notice of Meeting with NextEra Energy Seabrook, LLC2021-04-15015 April 2021 Notice of Meeting with NextEra Energy Seabrook, LLC Project stage: Request SBK-L-21067, License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements2021-07-21021 July 2021 License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements Project stage: Request SBK-L-21098, Supplement to License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements2021-09-22022 September 2021 Supplement to License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements Project stage: Supplement ML21245A4382021-10-0505 October 2021 Supplemental Information Needed for Acceptance of Requested Licensing Action Amendment to Revise 120-Volt AC Vital Instrument Panel Technical Specification Requirements Project stage: Acceptance Review ML21278A3092021-10-0606 October 2021 Acceptance of Requested Licensing Action Regarding Amendment to Revise 120-Volt AC Vital Instrument Panel Technical Specification Requirements Project stage: Acceptance Review ML22063A0002022-01-25025 January 2022 Requests for Additional Information from Risk Branch Regarding 120V Inverter LAR Project stage: RAI ML22062B6642022-02-0707 February 2022 Request for Additional Information 120V Inverter LAR from the Electrical Branch Project stage: RAI SBK-L-22024, Response to Request for Additional Information (Raj) Regarding License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements2022-03-0707 March 2022 Response to Request for Additional Information (Raj) Regarding License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements Project stage: Response to RAI ML22153A4152022-05-31031 May 2022 Request for Additional Information Re 120V Inverter LAR from TS Branch - Final Project stage: RAI L-2022-106, Revised Response to Request for Additional Information (RAI) Regarding License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements2022-06-27027 June 2022 Revised Response to Request for Additional Information (RAI) Regarding License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements Project stage: Response to RAI ML22230C9242022-09-30030 September 2022 Issuance of Amendment No. 170 Revision of 120-Volt AC Vital Instrument Panel Requirements Project stage: Approval 2022-01-25
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Category:E-Mail
MONTHYEARML23173A1522023-06-22022 June 2023 Request for Additional Information NextEra Fleet Emergency Plan Amendment Request ML23156A3042023-05-31031 May 2023 Acceptance of Requested Licensing Action Amendment Request to Remove Period of Applicability from Pressure Temperature Limits and Low Temperature Over Pressure Protection Curves ML23109A1862023-04-19019 April 2023 and Turkey Point Acceptance of Requested Licensing Action Proposed Alternative to Asme Section XI Authorizing Implementation of Asme Code Case N-752-1 ML23066A1892023-03-0303 March 2023 OEDO-22-00419: Email Dated 3-3-2023 to Petitioner on Seabrook ASR Petition ML23066A0892023-02-24024 February 2023 OEDO-22-00419 - Email Dated 02/24/2023 to Petitioner on Seabrook Unit 1 ASR Petition ML23020A9392023-01-19019 January 2023 Acceptance of Requested Licensing Action Amendment Request to Revise Cooling Tower Service Water Loop or Cell Requirements (EPID L-2022-LLA-0183) (Email) ML23011A3082023-01-11011 January 2023 Request for Additional Information Regarding Relief Request 4RA-22-001 (L-2022-LLR-0074) ML22341A0012022-12-0606 December 2022 Acceptance of Requested Licensing Action Relief Request 4RA-22-001, Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2) ML22333A7452022-11-22022 November 2022 OEDO-22-00419 - Email: C-10 Response on PRB Initial Assessment - C-10 Petition on Seabrook ASR Concrete Degradation ML22287A1472022-10-13013 October 2022 2.026 Petition Screen-in Email ML22228A0552022-08-15015 August 2022 Request for Additional Information Steam Generator Tube Inspection Report Review ML22200A1082022-07-19019 July 2022 Acceptance Review for TSTF-577 Amendment ML22153A4152022-05-31031 May 2022 Request for Additional Information Re 120V Inverter LAR from TS Branch - Final ML22116A2442022-04-26026 April 2022 Acceptance of Requested Licensing Action Relief Request 3IR-18 and 3IR-19 for End of Third 10-Year ISI Interval for Examinations with Limited Coverage ML22048B5522022-02-17017 February 2022 LTR-22-0010 Reply to Geoff Gilbert Email Concern About Seabrook Station Concrete Degradation ML22062B6642022-02-0707 February 2022 Request for Additional Information 120V Inverter LAR from the Electrical Branch ML22063A0002022-01-25025 January 2022 Requests for Additional Information from Risk Branch Regarding 120V Inverter LAR ML22020A2542022-01-20020 January 2022 LTR-22-0010 Geoff Gilbert, E-mail Concern About Seabrook Station Concrete Degradation ML21097A2512021-04-0707 April 2021 Request for Additional Information Regarding Steam Generator Tube Inspection Report Review for RFO 20 (EPID L-2020-LRO-0066) (Email) ML21054A0482021-02-23023 February 2021 Request for Additional Information Regarding Heat Flux Hot Channel Requirement Amendment Request ML20343A0942020-12-0303 December 2020 Request for Additional Information Regarding Seabrook (COVID-19) Part 73 Force-on-Force Exemption Request (L-2020-LLE-0219) ML20273A2812020-09-22022 September 2020 Acceptance of Requested Licensing Action License Amendment Request to Resolve Non-Conservative Heat Flux Hot Channel Factor Requiments ML20258A1502020-09-14014 September 2020 Request for Additional Information Related to Seabrook License Amendment Request Regarding One-Time Change to the AC Sources Operating TS ML20260H4932020-09-11011 September 2020 NRR E-mail Capture - Comanche Peak - Acceptance of Requested Licensing Action - Request to Use Later Code Edition of ASME OM Code ML20230A2962020-08-14014 August 2020 Acceptance of Requested Licensing Action License Amendment Request to Allow a One-Time Change to the AC Sources Operating TS ML20167A1842020-06-11011 June 2020 Request for Additional Information Related to Seabrook License Amendment Request Regarding TSTF-411 and TSTF-418 (L-2019-LLA-0237) ML20124A0012020-05-0101 May 2020 Cancellation of Call with Seabrook on Steam Generator Tube Inspections ML20114E1592020-04-23023 April 2020 Email and Request for Additional Information Related to Seabrook License Amendment Request to Degraded Voltage Time Delay Setpoint (L-2020-LLA-0012) ML20101N0932020-04-10010 April 2020 Acceptance of Requested Licensing Action Re Relief Request to Defer ASME Inspections Due COVID-19 (EPIDs L-2020-LLR-0055, -56, and -57) ML20101L0402020-04-10010 April 2020 Acceptance of Requested Licensing Action Relief Request to Use Code Case OMN-13 with 2012 Edition of the OM Code ML20101H3912020-04-0808 April 2020 Verbal Authorization for Seabrook Relief Request 3IIR-7 ML20087K8262020-03-27027 March 2020 Upcoming Steam Generator Tube Inservice Inspection ML20063J9792020-02-28028 February 2020 Acceptance of Requested Licensing Action Amendment Request to Revise Degraded Voltage Time Delay Setpoint ML19347C6732019-12-13013 December 2019 Acceptance of Requested Licensing Action Amendment Request to Adopt TSTF-418 ML19296D9122019-10-23023 October 2019 NRR E-mail Capture - Request for Additional Information Related to Seabrook Inverter Amendment (L-2019-LLA-0216) ML19295F5422019-10-15015 October 2019 NRR E-mail Capture - Seabrook Station, Unit No. 1 - Acceptance of Requested Licensing Action Amendment Request to Revise Onsite Power Distribution Requirements ML19275G7832019-10-0101 October 2019 Limited Appearance Statement from New Hampshire State Representative, Robert Harb Regarding the Seabrook Station Unit 1 License Amendment Application ML19270E6512019-09-27027 September 2019 Limited Appearance Statement from Joanna Hammond Regarding the Seabrook Station Unit 1 License Amendment Application ML19270E6542019-09-26026 September 2019 Limited Appearance Statement from Brian Campbell Regarding the Seabrook Station Unit 1 License Amendment Application ML19196A3592019-07-15015 July 2019 NRR E-mail Capture - Seabrook Station, Unit No. 1 - Acceptance of Requested Licensing Action Amendment Request to Revise the Emergency Core Cooling System Accumulator Technical Specifications ML19169A2412019-06-13013 June 2019 NRR E-mail Capture - Seabrook Station, Unit No. 1 - Acceptance of Requested Licensing Action Relief Requests for the Containment Building Spray Pump Flow and Vibration Testing (Epids L-2019-LLR-00 and L-2019-LLR-00) ML19162A0662019-06-0404 June 2019 Reply to Mr. Rick Jakious'S E-mail of 5-29-2019 to Stephen B. Comley Sr., We the People with Attachments ML19112A1782019-04-22022 April 2019 NRR E-mail Capture - Point Beach; Seabrook; Turkey Point - Acceptance of Requested Licensing Action Amendment Request to Revise Technical Specifications to Adopt TSTF-563 ML19101A4042019-04-11011 April 2019 NRR E-mail Capture - Point Beach; Seabrook; St. Lucie; Turkey Point - Acceptance of Licensing Action Relief Request to Use Encoded Phased Array Ultrasonic Examination Techniques for Ferritic and Austenitic Welds ML19070A2382019-03-10010 March 2019 LTR-19-0088 Maura Healey, Attorney General, the Commonwealth of Massachusetts, Ltr NextEras Requests for a License Amendment and Twenty-year Extension Prior to Issuance of a Final Decision in Adjudicatory Hearing on Concrete Degradation at ML19056A4522019-02-25025 February 2019 Comment from Philip Hurzeler Regarding the Emergency Petition Filed by C-10 on February 13, 2019 ML19056A4582019-02-25025 February 2019 Comment from Deborah A. Jones Regarding the Emergency Petition Filed by C-10 on February 13, 2019 ML19056A4602019-02-25025 February 2019 Comment from Lisa Conti Regarding the Emergency Petition Filed by C-10 on February 13, 2019 ML19050A2212019-02-19019 February 2019 NRR E-mail Capture - Seabrook Station, Unit No. 1 - Acceptance of Requested Licensing Action Relief Request Proposed Alternative 3IR-17 Implementation of an Extended Reactor Vessel Inservice Inspection Interval ML19050A3202019-02-13013 February 2019 Package from Stephen B. Comley, Sr. at February 13, 2019 Seabrook Station, Unit 1, Public Meeting 2023-06-22
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARML23318A0772023-11-14014 November 2023 Request for Information and Notification of Conduct of IP 71111.21.N.04, Age-Related Degradation, Reference Inspection Report 05000443/2024011 ML23173A1522023-06-22022 June 2023 Request for Additional Information NextEra Fleet Emergency Plan Amendment Request ML23011A3082023-01-11011 January 2023 Request for Additional Information Regarding Relief Request 4RA-22-001 (L-2022-LLR-0074) ML22311A5582022-11-22022 November 2022 Supplemental Information Needed for Acceptance of Requested Licensing Action Amendment Request for Cep ML22228A0552022-08-15015 August 2022 Request for Additional Information Steam Generator Tube Inspection Report Review ML22153A4152022-05-31031 May 2022 Request for Additional Information Re 120V Inverter LAR from TS Branch - Final ML22062B6642022-02-0707 February 2022 Request for Additional Information 120V Inverter LAR from the Electrical Branch ML22063A0002022-01-25025 January 2022 Requests for Additional Information from Risk Branch Regarding 120V Inverter LAR ML21245A4382021-10-0505 October 2021 Supplemental Information Needed for Acceptance of Requested Licensing Action Amendment to Revise 120-Volt AC Vital Instrument Panel Technical Specification Requirements ML21097A2512021-04-0707 April 2021 Request for Additional Information Regarding Steam Generator Tube Inspection Report Review for RFO 20 (EPID L-2020-LRO-0066) (Email) ML21054A0482021-02-23023 February 2021 Request for Additional Information Regarding Heat Flux Hot Channel Requirement Amendment Request ML20343A0942020-12-0303 December 2020 Request for Additional Information Regarding Seabrook (COVID-19) Part 73 Force-on-Force Exemption Request (L-2020-LLE-0219) ML20258A1502020-09-14014 September 2020 Request for Additional Information Related to Seabrook License Amendment Request Regarding One-Time Change to the AC Sources Operating TS ML20204A5422020-07-21021 July 2020 Request for Additional Information Related to Seabrook License Amendment Request Regarding Degraded Voltage Time Delay Setpoint ML20167A1842020-06-11011 June 2020 Request for Additional Information Related to Seabrook License Amendment Request Regarding TSTF-411 and TSTF-418 (L-2019-LLA-0237) ML20114E1592020-04-23023 April 2020 Email and Request for Additional Information Related to Seabrook License Amendment Request to Degraded Voltage Time Delay Setpoint (L-2020-LLA-0012) ML19296D9122019-10-23023 October 2019 NRR E-mail Capture - Request for Additional Information Related to Seabrook Inverter Amendment (L-2019-LLA-0216) ML18163A0352018-06-11011 June 2018 Requests for Additional Information for the Review of the Seabrook Station License Renewal Application ML18121A3992018-05-0101 May 2018 NRR E-mail Capture - Request for Additional Information Regarding ASR Amendment Request ML18113A5292018-04-18018 April 2018 NRR E-mail Capture - Draft - Request for Additional Information Regarding ASR Amendment Request ML18058A0522018-02-27027 February 2018 Enclosurequest for Additional Information (Letter: RAI Regarding Florida Power and Light/Nextera Decommissioning Funding Plan Updates for St. Lucie, Units 1 & 2; Seabrook Station; Duane Arnold Energy Center; and Point Beach, Units 1 and 2) ML18026A8792018-01-29029 January 2018 Final Requests for Additional Information for the Safety Review of the Seabrook Station License Renewal Application Docket No. 05-443 ML17332A3412017-11-29029 November 2017 Supplemental Information Needed for Acceptance of Requested Licensing Action Amendment to Delete Operator Action and Request for Exemption ML17261B2172017-10-11011 October 2017 Request for Additional Information Regarding License Amendment Request Related to Alkali-Silica Reaction (CAC No. MF8260; EPID L-2016-LLA-0007) ML17276B7572017-10-0202 October 2017 NRR E-mail Capture - Draft - Request for Additional Information Regarding ASR Amendment Request ML17214A0852017-08-0404 August 2017 Request for Additional Information Regarding License Amendment Request Related to Alkali-Silica Reaction ML17201Q1072017-07-18018 July 2017 NRR E-mail Capture - Draft - Request for Additional Information Regarding ASR Amendment Request ML17139B8352017-05-24024 May 2017 Final Request for Additional Information Regarding Seabrook License Renewal Application - Set 26 ML17150A2862017-05-0505 May 2017 NRR E-mail Capture - Draft - Request for Additional Information Regarding ASR Amendment Request ML17088A6142017-03-29029 March 2017 Request for Additional Information for the Review of the Seabrook Station License Renewal Application ML16341B9022017-03-0707 March 2017 03/07/2016 Summary of Telecon Held on Between the U.S. Nuclear Regulatory Commission and NextEra Energy Seabrook Concerning Request for Additional Information Pertaining to the Seabrook Station License Renewal Application ML16342C4672017-03-0101 March 2017 12/01/2016 Summary of Teleconference Between the U.S. Nuclear Regulatory Commission and NextEra Energy Seabrook Concerning Requests for Additional Information Pertaining to the Seabrook Station License Renewal Application ML16337A0082016-12-0101 December 2016 NRR E-mail Capture - Need for Supplement to ILRT License Amendment Seabrook Station, License Amendment Request 16-01, Request to Extend Containment Leakage Test Frequency ML16326A0372016-11-30030 November 2016 Requests for Additional Information for the Review of the Seabrook Station License Renewal Application ML16326A0092016-11-18018 November 2016 NRR E-mail Capture - Request for Additional Information Re. Nextera/Fpl LAR to Adopt TSTF-545 - CACs MF8203, MF8204, MF8208, and MF8209 ML16301A4282016-11-14014 November 2016 Requests for Additional Information for the Review of the License Renewal Application ML16319A4222016-11-10010 November 2016 NRR E-mail Capture - Need for Supplement to ILRT License Amendment ML16319A4212016-11-10010 November 2016 NRR E-mail Capture - Need for Supplement to EAL License Amendment ML16230A1062016-10-0303 October 2016 Request for Additional Information Request to Extend Containment Leakage Test Frequency ML16230A5332016-09-22022 September 2016 Request for Additional Information Amendment Request to Adopt Emergency Action Level Schemes Pursuant to NEI 99-01, Revision 6 ML16258A0222016-09-19019 September 2016 Supplemental Information Needed for Acceptance of Requested Licensing Action Alkali-Silica Reaction ML16187A2032016-07-0808 July 2016 Requests For Additional Information For The Severe Accident Mitigation Alternatives (SAMA) Review Of The Seabrook Station License Renewal Application (TAC No. Me3959)- Enclosure ML15328A1392015-12-0404 December 2015 November 23, 2015, Summary of Telephone Conference Call Held Between the U.S. Nuclear Regulatory Commission and Nextera Energy Seabrook, LLC, Concerning Requests for Additional Information Pertaining to the Seabrook Station ML15251A3332015-10-0202 October 2015 Request for Additional Information Related to the Review of the Seabrook Station, Unit 1, License Renewal Application-SET 25 ML15224A5662015-08-28028 August 2015 Request for Additional Information Related to the Review of the Seabrook Station License Renewal Application-Set 24 ML15131A3382015-06-0505 June 2015 Request for Additional Information Regarding License Amendment 14-03, Changes to Technical Specification 3.3.3.1,Radiation Monitoring for Plant Operations ML15043A2212015-02-24024 February 2015 Request for Additional Information for the Spring 2014 Steam Generator Tube Inspections ML14363A3672015-01-0909 January 2015 Request for Additional Information Regarding the License Amendment Request to Revise the Technical Specification Pressure-Temperature Limits and Request for Exemption from 10 CFR Part 50, Appendix G Minimum Tempt Requirements ML14358A0732014-12-24024 December 2014 Request for Additional Information for License Amendment Request 13-05. Fixed Incore Detector System Analysis Methodology ML14324A6372014-11-24024 November 2014 Request for Additional Information Regarding License Amendment Request to Increase Voltage Limit for Diesel Generator Load Rejection Surveillance Requirement 2023-06-22
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Text
From: Poole, Justin To: Mack, Jarrett; Levander, Matthew Cc: Danna, James
Subject:
Request for Additional Information RE: 120V Inverter LAR Date: Tuesday, May 31, 2022 4:07:00 PM Attachments: L-2021-LLA-0131 STSB RAIs final.pdf
- Jarrett, By letter dated July 21, 2021, as supplemented by letters dated September 22, 2021, and March 7, 2022 (Agencywide Documents Access and Management System (ADAMS)
Accession Number ML21202A238, ML21278A309, and ML22066B007, respectively),
NextEra Energy Seabrook, LLC (NextEra, the licensee) requested changes to the Technical Specifications (TSs) for Renewed Facility Operating License NPF-86 for Seabrook Station, Unit No. 1 (Seabrook). The proposed changes would revise TS 3/4.8.3, Onsite Power Distribution - Operating, by increasing the Allowed Outage Time (AOT) for the 120-volt (V) alternating current (AC) vital instrument panel inverters, establishing a new required action for two inoperable 120 VAC vital instrument panel inverters of the same electrical train and related administrative changes. In reviewing the submitted information, the U.S. Nuclear Regulatory Commission (NRC) staff has determined that additional information is necessary to complete its review.
On May 20, 2022, the NRC staff sent the licensee DRAFT RAIs to ensure that the questions are understandable, the regulatory basis is clear, there is no proprietary information contained in the RAIs, and to determine if the information was previously docketed. On May 31, 2022, the NRC and the licensee held a public meeting to discuss the DRAFT RAIs. During the meeting, the licensee requested a response date of 30 days from the date of this email. The NRC staff informed the licensee that this timeframe is acceptable. The attached is the final version of the RAIs. These RAIs will be put in ADAMS as a publicly available document.
Justin C. Poole Project Manager NRR/DORL/LPL I U.S. Nuclear Regulatory Commission (301)415-2048
REQUESTS FOR ADDITIONAL INFORMATION (RAIs) REGARDING THE LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION 3/4.8.3, ONSITE POWER DISTRIBUTION - OPERATING SEABROOK STATION, UNIT NO. 1 DOCKET NO. 50-443 By application dated July 21, 2021, and as supplemented by letters dated September 22, 2021, and March 7, 2022 (Agencywide Documents Access and Management System (ADAMS)
Accession Numbers ML21202A238, ML21278A309, and ML22066B007, respectively), NextEra Energy Seabrook, LLC (NextEra, the licensee) requested changes to the Technical Specifications (TSs) for Renewed Facility Operating License NPF-86 for Seabrook Station, Unit No. 1 (Seabrook). The proposed changes would revise TS 3/4.8.3, Onsite Power Distribution -
Operating, by increasing the Allowed Outage Time (AOT) for the 120-volt (V) alternating current (AC) vital instrument panel inverters, establishing a new required action for two inoperable 120 VAC vital instrument panel inverters of the same electrical train and related administrative changes. The Supplement dated September 22, 2021 superseded the July 21, 2021, application.
The NRC staff has determined that the following additional information is needed to complete the review of the Seabrook license amendment request.
Regulatory Requirements and Guidance The NRC staff used the following regulatory requirements to review the LAR:
Title 10 of the Code of Federal Regulations, Part 50 (10 CFR 50), Section 36, Technical specifications, requires, in part, that the applicants for a license authorizing operation of a production or utilization facility must include in their application proposed TSs. 10 CFR 50.36(c) requires that TS include items in five specific categories related to station operation. These categories are (1) Safety limits, limiting safety system settings, and limiting control settings, (2)
Limiting conditions for operation (LCOs), (3) Surveillance requirements (SRs), (4) Design features, and (5) Administrative controls. The proposed change to the Seabrook TS relates to the LCO category.
10 CFR 50.36(c)(2)(i), in part, stated that LCOs are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met.
NRC Staff RAIs EEEB RAI-5 In the licensees response to EEEB RAI-2(b), the licensee stated the following:
Specifically, in the event of two or more vital panel/inverter failures on the same electrical train due to the inoperability of the DC links to their associated inverters, the most likely scenario for the application of proposed ACTION d, the instrument panels would either remain energized from their normal inverter-powered Class 1 E qualified 480-volt MCCs or 125 VDC bus, or if power to the instrument panels were disrupted, their associated static transfer switches would shift power to their backup (aka maintenance) MCC power supplies, just as the case for a single inverter failure, and operating procedures direct manual transfer to the backup AC power supplies if required.
In the supplement dated September 22, 2021, the licensee had stated the following:
The UPS units consist of a rectifier section which converts three-phase 460V AC power to a nominal 125 VDC power and an inverter section which inverts the DC power to single phase 120 VAC power. The inverters (two per train) assure an uninterruptible supply of AC electrical power to the AC vital buses even if the 4.16 kV safety buses are de-energized. The common DC bus which connects the rectifier output, the battery bank, and the input of the inverter, is called the DC link. Blocking circuitry installed in each UPS unit connect the battery source to the internal DC bus and prevents the 125 VDC batteries from supplying the inverter section when ac power is available and is capable of supplying the required output. Should AC power become unavailable or degrade below the allowable voltage, the diode instantly conducts, linking the internal DC bus to the battery supply providing power to the inverter section..
The NRC staff understands that based on the description of the UPSs in the September 22, 2021, supplement, either the Class 1E 480 VAC MCC through the rectifier or the 125 VDC power source supplies DC power to the inverter/panel via the DC link. Once the DC link is not available, the Class 1E 480 VAC MCC or the 125 VDC power source can no longer supply power to the inverter/panel. This staffs understanding is not consistent with the above underlined statement in response to EEEB RAI-2(b). Please clarify this inconsistency between the September 22, 2021, supplement and the response to EEEB RAI-2(b).
EEEB RAI-6 In the supplement dated September 22, 2021, the licensee stated the following:
During the proposed AOT extensions, power to the affected vital instrument panel will be maintained such that the assumptions and inputs associated with plant safety analyses are unaffected. Thereby, the balance of prevention and mitigation strategies remains preserved.
It appears that, based on the above statement, the assumptions and inputs associated with Seabrooks safety analyses would be affected if power to the affected 120 VAC vital instrument panel was not maintained using a maintenance supply from a non-Class 1 E 480-volt AC motor control center during the proposed 7-day AOT. However, the NRC staff notes that the maintenance power supply is not required by the Seabrook TS LCO 3.8.3.1 and/or for the operability of the 120 VAC vital instrument panel.
Clarify what power supply is credited such that the assumptions and inputs associated with plant safety analyses are unaffected. Clarify whether the inoperability of one 120 VAC vital instrument panel and the proposed associated AOT extension in the proposed revised
TS 3.8.3.1 Action b will adversely affect any assumptions or inputs associated with Seabrooks safety analyses. If such assumptions or inputs will be affected, provide justification to ensure sufficient safety margin will continue to exist during the proposed AOT extension.
STSB RAI-1 In response to EEEB RAI-2(a), the licensee stated the following (in part):
The proposed TS Bases will also clarify that upon exiting ACTION d and entering ACTION b for the remaining inoperable inverter, the proposed 7-day AOT of ACTION b begins at the time of initial inoperability (rather upon exiting ACTION d).
The purpose of the TS bases is to provide an explanation for the TS requirements. According to 10 CFR 50.36(a)(1), while TS bases should be included in an application, they are not to become a part of the TS. NRC staff noted that the proposed TS bases for TS 3.8.3.1 Action d appear to introduce a requirement to enter Action b. This requirement is only in the TS bases, not the proposed TS, which increases the possibility for misinterpretation. Please describe the location of this requirement in the TS or update the proposed TS to clarify the requirement.
STSB RAI-2 The licensees response to RAI 2(c) states, in part, For the reasons discussed in the response to EEEB RAI-1, operating experience has shown that the restoration of at least one inverter within the 8-hour AOT of proposed ACTION d is unlikely. NRC staff noted that this statement is in contradiction to proposed Action d.2 of TS 3.8.3.1 which requires, in part, that at least two AC vital panels be energized from their associated inverters and DC buses within eight hours when two or more AC vital panels of the same train are inoperable. In light of this information, please explain how the actions in proposed Action d.2 would meet the intent of 10 CFR 50.36(c)(2)(i) which states, in part, When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met.