ML091740231

Post Accident Monitoring (Pam) Report

ML091740231
Person / Time
Site:	North Anna
Issue date:	06/17/2009
From:	Stoddard D Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
09-359
Download: ML091740231 (3)

Text

VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 June 17, 2009 U.S. Nuclear Regulatory Commission Serial No.09-359 Attention: Document Control Desk NAPS: MPW Washington, D.C. 20555 Docket Nos. 50-338 License Nos. NPF-4 Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

NORTH ANNA POWER STATION UNIT 1 POST ACCIDENT MONITORING (PAM) REPORT On May 11, 2009, with Unit 1 in Mode 1 at 100 percent power, the open red indication light for the Phase B containment isolation valve (CIV) 1-CC-TV-102C ("B" RCP CC Return Outside Isolation) was determined to be inoperable. This Regulatory Guide 1.97 CIV is located outside of containment in the component cooling (CC) water return line from the "B" Reactor Coolant Pump (RCP). The closed green light indication is operable. The cause of the inoperable red open light is a missing rubber insulating ring in the socket. Technical Specification (TS) 3.3.3 Condition "A" requires restoration of the CIV indication to operable within thirty days. If CIV indication is not returned to service within thirty days, a Post Accident Monitoring Report is required in accordance with TS 5.6.6. This letter provides the required report and includes our plan and schedule for restoring the CIV indication to service.

Other indicators are available that provide verification of the CIV in the closed position if a containment isolation signal is received. There has been no change in CC system flow from the "B" RCP to indicate any mechanical problem from the valve. The CIV cycled properly during its last valve position indication test completed on March 30, 2009. The CIV located inside containment (1-CC-TV-102D) was also cycled properly during the last valve position indicator test completed on March 29, 2009. If a containment depressurization actuation (CDA) were to occur, both the inside and outside CIVs would receive a signal to close. The outside CIV would be verified closed using alternate indication.

This is a valve position open indication operability issue only. The replacement of the bulb with the rubber insulating ring missing in the bulb socket on-line can lead to grounding of the circuit, and possibly result in the associated trip valve closing which would be detrimental to Unit 1 operation. Therefore, due to the inherent risks involved with performaing maintenance on-line and our safety standards requiring the missing rubber insulating ring to be installed in the socket to prevent grounding, repairs are scheduled to be performed at the first entry into a unit condition of sufficient duration to allow the repair. The risks associated with performing repairs on-line include maintenance in a sensitive area (i.e., Control Room Safeguards Equipment Panel) and

Serial No.09-359 Docket No. 338 PAM Report Page 2 of 3 by-passing the air supply to the CIV to prevent the CIV from inadvertently closing, which may require manually tripping the reactor and shutting down the running "B" RCP.

Initial conditions for the valve testing and the position indication periodic test require the unit to be in Modes 5 or 6 or defueled with the RCP secured.

Continued operation of this valve is permitted because there are several levels of alternate indication. The Plant Computer System (PCS) provides an alternate reliable indication (PCS computer point S1CCO17D, "B" RCP Return Header Valve") to determine valve position. Flow indicators will also indicate zero flow in the CC return line when 1-CC-TV-102C is closed.

This report has been reviewed and approved by the Facility Safety Review Committee.

If you have any questions or require additional information, please contact Mr. Page Kemp at (540) 894-2295.

Sincerely, Daniel G. Stoddard, P.E.

Site Vice President Commitments made in this letter: None

Serial No.09-359 Docket No. 338 PAM Report Page 3 of 3 cc: U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 NRC Senior Resident Inspector North Anna Power Station Mr. J. F. Stang, Jr.

NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 0-8 G9A Rockville, Maryland 20852-2738 Ms. D. N. Wright NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 0-8 H4A Rockville, Maryland 20852-2738