DCL-20-108, Use of Risk-Informed Evaluation Methodology to Address Open Phase Condition

Use of Risk-Informed Evaluation Methodology to Address Open Phase Condition

ML20364A208
Person / Time
Site:	Diablo Canyon
Issue date:	12/29/2020
From:	Gerfen P Pacific Gas & Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
DCL-20-108
Download: ML20364A208 (3)

Text

mPacHic Gas and Electric Company*

Pa ula Gerfen Site Vice President Diablo Canyon Power Plant Mail code 104/6/605 P.O. Box 56 Avila Beach, CA 93424 805.545.4596 Internal: 691.4596 Fax: 805.545.4234 December 29, 2020 PG&E Letter DCL-20-108 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Use of Risk-Informed Evaluation Methodology to Address Open Phase Condition

References:

1. PG&E Letter DCL-19-097, Schedule Extension for Full Implementation of Open Phase Detection System, dated December 9, 2019 (ML19343B177)

2. Nuclear Energy Institute Open Phase Condition Initiative, Revision 3, dated June 2019 (transmitted to NRC under NEI letter dated June 6, 2019, Douglas E.

True to Ho Nieh, Jr., re: Industry Initiative on Open Phase Condition, Revision 3) (ML19163A176)

3. PG&E Letter DCL-14-118, Supplement to Response to NRC Request for Additional Information Regarding Response to NRC Bulletin 2012-01, dated December 22, 2014 (ML14356A571)

Dear Commissioners and Staff:

Reference 1 noted that Pacific Gas and Electric Company (PG&E) would inform the NRC if PG&E opted to implement the risk-informed evaluation methodology in Reference 2 to address potential open phase conditions (OPCs) at Diablo Canyon Power Plant (DCPP). PG&E has decided to implement that methodology.

Implementation will be completed by March 31, 2021.

This submittal revises PG&Es OPC commitment, as originally made in Reference 3.

The enclosure restates the superseded and revised commitments for clarity.

If you have any questions or require additional information, please contact Mr. Jim Morris, DCPP Regulatory Services Manager, at 805-545-4609.

A m em ber of t he STARS Al l i a n ce Ca l l a w a y

• D i a b lo Ca n yo n

• P a l o Ve r de

• W o l f Cr e e k

Document Control Desk PG&E Letter DCL-20-108 December 29, 2020 Page 2 Sincerely,

~~TO Paula Gerfen Site Vice President jmsp/51068100-02 Enclosure cc: Donald R. Krause, NRC Senior Resident Inspector Samson S. Lee, NRC Project Manager Scott A. Morris, NRC Region IV Administrator Diablo Canyon Distribution A m em ber of t he STARS Al l i a n ce Ca l l a w a y

• D i a b lo Ca n yo n

• P a l o Ve r de

• W o l f Cr e e k

Enclosure PG&E Letter DCL-20-108 Regulatory Commitment Summary Superseded Commitment - quoted from Reference 3 with dates (in brackets) from Reference 1:

PG&E is committed to the following schedule for implementation of the Open Phase Detection system:

• Unit 1 [t]rip functions will be enabled by [December 31, 2020].

• Unit 2 [t]rip functions will be enabled by [December 31, 2020].

Revised Commitment:

PG&E will implement the risk-informed evaluation methodology in Reference 2 (Nuclear Energy Institute Open Phase Condition Initiative, Revision 3, dated June 2019, ML19163A176) in conjunction with NEI 19-02, Revision 1, to address potential open phase conditions (OPCs) at Diablo Canyon Power Plant (DCPP). Implementation will be completed by March 31, 2021.

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