ML052170268

RAI, Increase Completion Times for ECCS-LHSI, AFW Quench Spray and Chemical Addition Systems

ML052170268
Person / Time
Site:	North Anna
Issue date:	08/09/2005
From:	John Honcharik NRC/NRR/DLPM/LPD2
To:	Christian D Virginia Electric & Power Co (VEPCO)
Honcharik , J., DE/EMCB
References
Download: ML052170268 (5)

Text

August 9, 2005 Mr. David A. Christian Sr. Vice President and Chief Nuclear Officer Virginia Electric and Power Company Innsbrook Technical Center 5000 Dominion Blvd.

Glen Allen, Virginia 23060-6711

SUBJECT:

NORTH ANNA POWER STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO INCREASE COMPLETION TIMES FOR ECCS-LHSI, AFW, QUENCH SPRAY AND CHEMICAL ADDITION SYSTEMS

Dear Mr. Christian:

By letter dated December 17, 2004, Virginia Electric and Power Company (VEPCO) submitted a proposed license amendment request to change the Technical Specifications by increasing the completion times for the Emergency Core Cooling System-Low Head Safety Injection subsystem, Auxiliary Feedwater, Quench Spray and Chemical Addition Systems from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days for North Anna Power Station, Units 1 and 2. Based on its review of the December 17, 2004, submittal, the NRC staff has determined that additional information for the Auxiliary Feedwater System is required to complete its review.

The NRC staffs questions are provided in the Enclosure. VEPCO is requested to provide a response to the request for additional information within 60 days of the date of this letter.

Sincerely,

/RA/

John Honcharik, Project Manager, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-338 and 50-339

Enclosure:

As stated cc w/encl: See next page

ML052170268 NRR-088 OFFICE PDII-1/PM PDII-2/LA PDII-1/SC NAME JHoncharik CHawes EMarinos DATE 8/8/05 8/8/05 8/9/05 REQUEST FOR ADDITIONAL INFORMATION PROPOSED LICENSE AMENDMENT REQUEST TO INCREASE THE COMPLETION TIMES FOR THE ECCS-LHSI, AFW, QUENCH SPRAY AND CHEMICAL ADDITIONS SYSTEMS FOR NORTH ANNA, UNITS 1 AND 2 VIRGINIA ELECTRIC AND POWER COMPANY DOCKET NOS. 50-338 AND 50-339 By letter dated December 17, 2004, Virginia Electric and Power Company submitted a proposed license amendment request to change the Technical Specifications (TS) by increasing the completion times (CTs) for the Emergency Core Cooling System-Low Head Safety Injection subsystem, Auxiliary Feedwater (AFW), Quench Spray and Chemical Addition Systems from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days for North Anna Power Station, Units 1 and 2. Attachment 1 to the letter dated December 17, 2004, provides a discussion on the proposed changes to the TS.

The NRC staff has the following requests for additional information on the AFW system.

1. The proposed CT change for TS 3.7.5 will allow parts of the AFW system to be unavailable for additional time, while inoperable equipment is being restored. There is a need to determined how this unavailability will impact plant safety and operation.

As pointed out below, explain how the impact of the proposed CT change is consistent with maintaining the following attributes of the defense-in-depth (DID) philosophy for the AFW system. In addressing each DID attribute, explain the basis for the conclusion reached.

a. A reasonable balance is preserved among prevention of core damage, prevention of containment failure, and consequence mitigation.

For this attribute, address the part referring to consequence mitigation.

Since the proposed completion time change extends the time that one AFW system train is inoperable, explain how consequence mitigation associated with AFW train inoperability remains unaffected using an example (e.g., mitigating loss of main feedwater).

b. System redundancy, independence, and diversity are preserved commensurate with the expected frequency, consequences of challenges to the system, and uncertainties.

On page 11 of the license amendment request, the licensee states that the North Anna probabilistic risk assessment model requires AFW for decay heat removal for all events except for large loss-of-coolant (LOCA). Success criteria is 1 of 3

2 AFW pumps for all events requiring the AFW system for decay heat removal, except for 1) station blackout which requires 1 of 1 TD pump and 2) for small and medium LOCAs with HHSI failure which requires 2 of 3 AFW pumps.

The frequency of small and medium LOCAs is high and the consequences of a station blackout event with an inoperable turbine-driven pump are very significant.

Given the proposed completion time change, explain how maintaining the redundancy and diversity of the AFW system will be affected for event challenges to the system, as noted above. In particular, address the inoperability of a turbine-driven pump.

2. The proposed CT changes will make the CT to be 7 days and the total time from discovery of the failure to meet the limiting condition for operation to be 14 days for Required Actions A.1 and B.1 of TS 3.7.5. Since the completion time and the total time are the same for the two required actions, address making Required Actions A.1 and B.1 into a single action with an action condition that states one AFW train inoperable in MODE 1, 2 or 3.

North Anna Power Station, Units 1 & 2 cc:

Mr. C. Lee Lintecum Mr. Jack M. Davis County Administrator Site Vice President Louisa County North Anna Power Station Post Office Box 160 Virginia Electric and Power Company Louisa, Virginia 23093 Post Office Box 402 Mineral, Virginia 23117-0402 Ms. Lillian M. Cuoco, Esq.

Senior Counsel Dr. Robert B. Stroube, MD, MPH Dominion Resources Services, Inc. State Health Commissioner Building 475, 5 th floor Office of the Commissioner Rope Ferry Road Virginia Department of Health Waterford, Connecticut 06385 Post Office Box 2448 Richmond, Virginia 23218 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation Post Office Box 1197 Richmond, Virginia 23218 Old Dominion Electric Cooperative 4201 Dominion Blvd.

Glen Allen, Virginia 23060 Mr. Chris L. Funderburk, Director Nuclear Licensing & Operations Support Dominion Resources Services, Inc.

Innsbrook Technical Center 5000 Dominion Blvd.

Glen Allen, Virginia 23060-6711 Office of the Attorney General Commonwealth of Virginia 900 East Main Street Richmond, Virginia 23219 Senior Resident Inspector North Anna Power Station U. S. Nuclear Regulatory Commission 1024 Haley Drive Mineral, Virginia 23117