ML16358A715

Response to Request for Additional Information Regarding Emergency License Amendment Request for a One-Time Extension of the Diesel Generator Completion Time

ML16358A715
Person / Time
Site:	Palo Verde
Issue date:	12/23/2016
From:	Rash B Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-07410-MLL/TNW
Download: ML16358A715 (2)

Text

10 CFR 50.90 Bruce Rash Vice President, Nuclear Engineering Palo Verde Nuclear Generating Station P.O. Box 52034 102-07410-MLL/TNW Phoenix, AZ 85072 December 23, 2016 Mail Station 7605 Tel 623.393.5102 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

Reference:

Arizona Public Service Company Letter 102-07406, Emergency License Amendment Request for a One-Time Extension of the Diesel Generator Completion Time, dated December 21, 2016 [Agency Documents Access and Management System (ADAMS) Accession No. ML16356A689]

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 3 Docket No. STN 50-530 Renewed Operating License No. NPF-74 Response to Request for Additional Information (RAI) Regarding Emergency License Amendment Request (LAR) for a One-Time Extension of the Diesel Generator Completion Time In accordance with the provisions of Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR), Arizona Public Service Company (APS) submitted the referenced letter requesting an emergency license amendment for a one-time extension of the emergency diesel generator (DG) completion time described in the Technical Specifications (TS) for Palo Verde Nuclear Generating Station (PVNGS) Unit 3 from 10 days to 21 days.

The following additional items are being provided in response to a request for additional information conveyed to APS in a telephone discussion today with the acting NRC Branch Chief:

NRC Question #1: Are the compensatory measures described in Attachment #3 of Enclosure 1 of the referenced letter formal NRC commitments?

APS Response: The compensatory measures described in Attachment #3 were not originally identified in the referenced letter as formal NRC commitment. APS agrees to identify and control these compensatory measures as formal NRC commitments.

A member of the STARS Alliance LLC Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

102-07410-BR/TNW ATTN: Document Control Desk U. S. Nuclear Regulatory Commission RAI Response for a One-Time Extension of the Diesel Generator Completion Time Page 2 NRC Question #2: Describe the actions that will be taken if it is discovered that a common mode failure exists for the Unit 3A Diesel Generator (DG)?

APS Response: APS is performing an extensive causal analysis of the Unit 3B DG failure.

To date, APS has no evidence or reason to suspect that there is a common mode failure.

In the event the causal analysis of the Unit 3B DG determines a common failure mode does exist in the redundant Unit 3A DG, condition E of TS 3.8.1 will be entered for two inoperable DGs and the required actions will be taken in accordance with PVNGS TS.

NRC Question #3: Please describe the operations resources needed to ensure the actions can be taken within the time allotted.

APS Response: An additional regulatory commitment is made regarding assignments for the Unit 3 on-shift Operations complement. These do not require assignment of additional staff to the typical on-shift Operations staffing levels:

• An auxiliary operator (AO) on each shift will be dedicated to perform pre-start checks of the portable generators each shift. This dedicated AO will perform the emergency start of the portable generators when directed and monitor their operation. The dedicated AO will have no other assigned duties during the extended completion time.

• In the event of a reactor trip with a loss of off-site power, the Area 4 (Control Building) AO, will perform the required electrical system alignments, as directed by the control room, to restore power to the B train Class 1E 4.16 kv bus using the portable generators, in accordance with station procedures.

• In the event of a reactor trip with a loss of off-site power, one of the on-shift reactor operators will be assigned to perform and direct actions to restore power to the B train Class 1E 4.16 kv bus using the portable generators. During the event, this reactor operator will not be assigned other duties until completion of power restoration.

Should you have any questions concerning the content of this letter, please contact Thomas Weber, Department Leader, Nuclear Regulatory Affairs, at (623) 393-5764.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on : December 23, 2016__

(Date)

Sincerely, Digitally signed by Rash, Bruce Rash, Bruce (Z77439)

DN: cn=Rash, Bruce (Z77439) (Z77439)

Date: 2016.12.23 13:49:26 -07'00' BR/TNW/DCE cc: K. M. Kennedy NRC Region IV Regional Administrator S. P. Lingam NRC NRR Project Manager for PVNGS M. M. Watford NRC NRR Project Manager C. A. Peabody NRC Senior Resident Inspector for PVNGS T. Morales Arizona Radiation Regulatory Agency (ARRA)