ML21189A066

NRR E-mail Capture - Additional Draft Request for Additional Information - Diablo Canyon Emergency Amendment Request to Revise Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System

ML21189A066
Person / Time
Site:	Diablo Canyon
Issue date:	07/07/2021
From:	Samson Lee NRC/NRR/DORL/LPL4
To:	Richardson M Pacific Gas & Electric Co
References
L-2021-LLA-0123
Download: ML21189A066 (2)

Text

From: Lee, Samson Sent: Wednesday, July 7, 2021 5:07 PM To: Richardson, Michael

Subject:

Additional DRAFT request for additional information - Diablo Canyon emergency amendment request to revise Technical Specification 3.7.8, Auxiliary Saltwater (ASW) System (EPID L-2021-LLA-0123)

Michael, Below is an additional DRAFT request for additional information (RAI) for the Diablo Canyon emergency license amendment request for the Auxiliary Saltwater (ASW) System. Please let me know if you need a clarification call. We expect an RAI response soon today.

Thanks, Sam

Background:

By letter dated July 7, 2021, Pacific Gas and Electric Company (PG&E or the licensee) submitted an emergency license amendment request (LAR) to revise the Technical Specification (TS) for the Diablo Canyon Nuclear Power Plant, Units 1 (Diablo Canyon or DCPP) (ADAMS Accession No. ML21188A214). The proposed amendments would provide a new TS 3.7.8 Condition A note to allow a one-time Completion Time (CT) of 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br /> to replace the ASW pump 1-1 motor during Cycle 23. The July 7, 2021, letter contains the same information as in the advance draft copy provided to the staff earlier the same day, except for administrative corrections in the proposed TS pages.

Risk Insights:

RAI APLA-2 In the LAR, Section 3 under Risk Insights, it was stated that, The results demonstrate that ICCDP [incremental conditional core damage probability] and ICLERF [incremental conditional large early release frequency] are below the risk significance criteria of Regulatory Guide 1.174, 1.0E-06 and 1.0E-07, respectively. Therefore, the proposed separate one-time extension of TS 3.7.8 Condition A Required Action to 6-days for emergent maintenance for ASW Pump 1-1 Motor is considered to not be risk significant. It was not clear to the staff which measure of risk was used since Regulatory Guide (RG) 1.174 refers to CDF/LERF and CDF/LERF.

a. Clarify if ICLERP was intended in lieu of ICLERF and if so, should Regulatory Guide 1.177 guidance on iCCDP/iCLERP be cited for this one-time TS change?

b. If not, justify how RG 1.174 metrics were used to conclude that maintenance on ASW Pump 1-1 Motor is not risk significant.

Hearing Identifier: NRR_DRMA Email Number: 1261 Mail Envelope Properties (SA1PR09MB8653565788953DC54EB27B629A1A9)

Subject:

Additional DRAFT request for additional information - Diablo Canyon emergency amendment request to revise Technical Specification 3.7.8, Auxiliary Saltwater (ASW) System (EPID L-2021-LLA-0123)

Sent Date: 7/7/2021 5:06:52 PM Received Date: 7/7/2021 5:06:00 PM From: Lee, Samson Created By: Samson.Lee@nrc.gov Recipients:

"Richardson, Michael" <MJRm@pge.com>

Tracking Status: None Post Office: SA1PR09MB8653.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1940 7/7/2021 5:06:00 PM Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: