ML120610161

Diablo Canyon Power Plant, Units 1 and 2 - Email, Request for Additional Information, License Amendment Request 11-06, Revision to Technical Specification 3.3.5, Loss of Power Diesel Generator Start Instrumentation. (TAC Nos. ME7520 and ME7

ML120610161
Person / Time
Site:	Diablo Canyon
Issue date:	03/01/2012
From:	Joseph Sebrosky Plant Licensing Branch IV
To:	Soenen P R Pacific Gas & Electric Co
Sebrosky J M, NRR/DORL/LPL4, 415-1132
References
TAC ME7520, TAC ME7521
Download: ML120610161 (2)

Text

From: Sebrosky, Joseph Sent: Thursday, March 01, 2012 10:32 AM To: Soenen, Philippe R Cc: Wang, Alan; Lent, Susan; Burkhardt, Janet; Sahay, Prem; Baldwin, Thomas (DCPP)

Subject:

Request for Additional information for DCPP regarding TS 3.3.5 (ME7520 and ME 7521) Philippe, By letter dated October 10, 2011, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML113010196), Pacific Gas and Electric Company (PG&E) submitted PG&E Letter DCL-11-072, "License Amendment Request 11-06 Revision to Technical Specification 3.3.5, 'Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation'." PG&E submitted a request for revision to Facility Operating License Nos. DPR-80 and DPR-82, revising Technical Specification (TS) 3.3.5 and final safety analysis report update (FSARU)

Appendix 6.2D and Sections 6.3, 15.3, and 15.4, revise the loss-of-coolant accident (LOCA) control room operator and offsite dose analysis of record described in the FSARU, and provide a new process for revising input values to this analysis.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided in your application and determined that the following additional information is required in order to complete its review. This request for additional information (RAI) was discussed with you on February 29, 2012. It was agreed that a response to this RAI would be provided by March 30, 2012. Should the NRC determine that this RAI is no longer necessary prior to this date, the request will be withdrawn. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1132 or via e-mail at joseph.sebrosky@nrc.gov. The NRC staff has determined that no security-related or proprietary information is contained herein.

Request for Additional Information

1. Page 2 in Enclosure PG&E Letter DCL-11-072 of LAR states, "The current TS 3.3.5.3 Surveillance Requirement (SR) contains First Level Undervoltage Relay (FLUR)

Technical Specification (TS) limits that are non-conservative for protection of engineered safety features (ESF) components during postulated sustained degraded grid voltage conditions in that some ESF equipment could trip on overcurrent and not be able to restart without operator action." Provide a list of ESF components that could trip on overcurrent due to sustained degraded grid voltage conditions and due to the existing nonconservative FLUR TS limits as stated above. Provide a summary of justification on how the proposed changes in TS SR 3.3.5.3.a for FLUR setpoint would prevent all ESF equipment from tripping on overcurrent and would prevent loss of ESF function. 2. Page 12 in Enclosure PG&E Letter DCL-11-072 of LAR states, "PG&E has analyzed the coordination between motor overcurrent protection settings and 4.16 kilo Volt (kV) bus undervoltage protection scheme and verified that the FLUR / Second Level Undervoltage Relay (SLUR) bus undervolatge protection function actuates before individual motor overcurrent protective devices. Thus, a sustained degraded voltage condition will not result in the loss of an ESF function-." Provide a summary and a copy of coordination study demonstrating that the FLUR/SLUR bus undervoltage protection device actuates before individual motor overcurrent protective devices and a sustained degraded voltage condition will not result in the loss of an ESF function. 3. Provide a summary and a copy of the coordination study for the largest load and also the most limiting component to show that starting or running these loads do not actuate protective devices and enough margins exist before any thermal damage occurs.