m Pacific Gas and ~8~ · Electric Company®

November 19, 2014

PG&E Letter DCL-14-107

Barry S. Allen Site Vice President

Diablo Canyon Power Plant Mail Code 104/6 P. 0. Box 56 Avila Beach, CA 93424

805.545.4888 Internal: 691.4888 Fax: 805.545.6445

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

10 CFR 50.4

Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Diablo Canyon Power Plant Licensing Basis Verification Project­Change in Commitment Regarding Component Design Basis Reviews

Reference:

1. PG&E Letter DCL-1 0-064, "Diablo Canyon Power Plant Licensing Basis Verification Project," dated June 11, 2010.

Dear Commissioners and Staff:

In Pacific Gas and Electric Company (PG&E) Letter DCL-10-064 (Reference 1), PG&E provided the NRC with the scope of component design basis reviews (CDBRs) that would be completed as part of the Licensing Basis Verification Project (LBVP) Phase II. The CDBRs are modeled after the reviews conducted using NRC Inspection Procedure 71111.21, "Component Design Bases Inspection," as a guide. In Reference 1, PG&E stated that the scope and schedule of the CDBRs would be adjusted if issues identified so warranted.

PG&E is revising the commitment regarding the number of CDBRs to be completed from eight to five. PG&E has completed CDBRs for the component cooling water system, the 230 kV system, the 500 kV system, the emergency diesel generator system, and the auxiliary feedwater system. The CDBRs identified in Reference 1 that will not be conducted are for the residual heat removal system, the solid state protection system, and the auxiliary saltwater system.

The scope of the LBVP for each system reviewed includes a verification of the licensing basis and a validation of the Final Safety Analysis Report, including implementing documents (e.g., plant procedures, design drawings, and calculations). CDBRs are then performed on the selected systems. As a result of this process, the CDBRs provide a deeper, more focused look at the · components because they benefit from the verification and validation of the licensing and design basis. The reviews to date have identified a number of issues and all have been entered into the Corrective Action Program. Although PG&E continues to evaluate

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance

Callaway • Comanche Peak • Diablo Canyon • Palo Verde • Wolf Creek

Document Control Desk November 19, 2014

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PG&E Letter DCL-14-107

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and address the findings from the CDBRs, no findings to date from the recent CDBRs have been concluded to be greater than low safety significance. As a result, PG&E has decided to reduce the scope from eight CDBRs to five.

This letter contains a change to the scope of the CDBRs being completed for a prior PG&E regulatory commitment to perform the Diablo Canyon Power Plant (DCPP) LBVP.

Questions concerning the DCPP LBVP should be directed to Mr. Eric Nelson at (805) 545-4777.

Sincerely,

8~:1en .7. AIL-Site Vice President

JY1 E/4609/50330504

cc: Marc L. Dapas, NRC Region IV Administrator Thomas R. Hipschman, NRC Senior Resident Inspector Ronald A. Kopriva, Senior Reactor Inspector Eric R. Oesterle, NRR Project Manager Eric P. Nelson, Senior Manager, LBVP

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance

Callaway • Comanche Peak • Diablo Canyon • Palo Verde • Wolf Creek