ML20080K856

Submits Notification for Spillway EDG Corrective Maint & Start Failure for Plant Hydroelectric Project

ML20080K856
Person / Time
Site:	North Anna
Issue date:	02/22/1995
From:	Saunders R VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	FEDERAL ENERGY REGULATORY COMMISSION
References
F95-005, F95-5, NUDOCS 9503010366
Download: ML20080K856 (3)

Text

'.

Y:722"Ti"e s' y February 22, 1995 WRGINIA POWER  ;

Mr. R. W. Crisp Serial No. F95-005 Regional Director Federal Energy Regulatory Commission 3125 Presidential Parkway, Suite 300 Atlanta, Georgia 30340

Dear Mr. Crisp:

PROJECT NO. 6335-VA NORTH ANNA HYDROELECTRIC PROJECT NOTIFICATION FOR SPILLWAY EMERGENCY DIESEL GENERATOR CORRECTIVE MAINTENANCE AND START FAILURE Pursuant to the requirements of 18 CFR 12.10(a)(2), Written Reports, and your December 30,1994 letter to Mr. J. P. O'Hanlon of Virginia Power, notification to FERC is required at least 10 days in advance of plans to remove any public safety device.

Furthermore, as stated in our letter to FERC dated April 7,1993 (Serial No. F93-003),

it is our goal to maintain equipment in optimal conditions at all times by addressing equipment problems immediately. Accordingly, this report documents the removal of the Spillway Emergency Diesel Generator (SEDG) from service to perform certain minor corrective maintenance.

A slight leak (i.e. an occasional drip) was identified at the fuel oil line fitting between the level switch tubing and the diesel fuel oil day tank. Prior to removing the SEDG from service to facilitate repairs, an unexpected automatic start occurred on January ,

31,1995. Subsequently, the SEDG failed to start during operability verification. Initial  !

investigation identified threa start circuit wires with degraded solder and/or lug connections. These wires were repaired and the SEDG was successfully started three consecutive times. Performance of the associated periodic test verified SEDG operability. The level switch, tubing, and fitting were removed from the fuel oil tank and cleaned. A sealant was applied to the threaded connections and the components were re-installed.

This event was reported by telephone to the Federal Energy Regulatory Commission at 1800 hours0.0208 days <br />0.5 hours <br />0.00298 weeks <br />6.849e-4 months <br /> on January 31,1995. The Nuclear Regulatory Commission was also contacted by telephone at 1805 hours0.0209 days <br />0.501 hours <br />0.00298 weeks <br />6.868025e-4 months <br /> on January 31, 1995, in accordance with 10 CFR 50.72(b)(2)(vi).

I l ,

200025 UI 9503o1o366 95o222 PDR PROJ i 6335A PDR I

On' February 7,1995, the SEDG experienced a second unexpected automatic start.

, Operability verification was successful upon satisfactory completion of the periodic test. Probable causes for the unexpected starts include activation of an automatic start i timer in the auto transfer switch cabinet and an automatic start logic which is tied to voltage drops in the normal power supply lines operated by Rappahanock Electric ,

Cooperative (REC). During troubleshooting activities, inquiries to REC indicated no voltage drops on the normal power supply lines when the SEDG unexpectedly started.

The auto start timer was originally installed for weekly functional tests when the dam was to be unmanned. The timer had been previously de-activated by removing the timer setting pins. The timer will be physically disconnected and removed as an additional precautionary measure. Removal of the timer from the auto transfer switch  !

cabinet is expected to preclude further unexpected starts. .

Certain start circuitry wires identified during troubleshooting had been spliced during previous maintenance activities. These wires are different from those that caused the auto start failure on January 31,1995. Testing indicated these wires were performing as designed. The wires were replaced as a precautionary measure. Following trouble-shooting activities, the SEDG was verified operable and was returned to service.

The equipment manufacturer was contacted to discuss other potential enhancements and precautionary measures for the SEDG in an effort to preclude future start failures.

Several recommendations resulting from those discussions are under review. Any ,

modifications deemed necessary or prudent for the SEDG will be communicated to '

your office in accordance with 18 CFR 12.11. ,

Should you have any questions regarding this report, please contact us.

Very truly yours, l

l R. F. Saunders l

i j

p :.

, r 6

e* l oc.' - U.SJNuclear Regulatory Commission .

Attn: Document Control Desk .  !

Washington, D. C. 20555 License Numbers: NPF-4/NPF-7 Docket Numbers: 50-338/50-339  !

U.S. Nuclear Regulatory Commission .;

Region il  :

101 Marietta Street, N.W. . -!'

Suite 2900 Atlanta, Georgia 30323 1 Mr. R. D. McWhorter &

NRC Senior Resident inspector  ;

North Anna Power Station '

i t

.F i

f i

b h

t 9

!