ML19332G047

Special Rept:On 891202,Kaman Process Vent Radiation Monitor Exceeded Action Statement of Tech Spec 3.3.3.1 Since Monitor Not Returned to Operable Status within 7 Days.On 891125, Monitor Alarmed in Control Room Every 15 to 30 Minutes

ML19332G047
Person / Time
Site:	North Anna
Issue date:	12/11/1989
From:	Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
89-844, NUDOCS 8912200078
Download: ML19332G047 (2)

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VIRGINIA ELECTRIC AND POWER COMI'ANY RICHMOND, VIRGINIA 23261 l December 11, 1989 i

U.S. Nuclear Regulatory Commission Serial No. 89 844 Attention: Document Control Desk NO/DEQ/deq Washington, D.C. 20555 Docket Nos. 50 338 50 339-License Nos. NPF 4 NPF-7 Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 SPECIAL REPORT - KAMAN PROCESS VENT >

RADIATION MONITOR - RI GW-178 5

At 1627 hours0.0188 days <br />0.452 hours <br />0.00269 weeks <br />6.190735e-4 months <br /> on December 2,1989, with Units 1 and 2 at 98 and 100 percent power (Mode 1), respectively, the Kaman Process Vent Radiation Monitor, RI GW-178, 2 exceeded the Action Statement of Technical Specification 3.3.3.1. Since the Action ,

Statement requires that the radiation monitor be returned to operable status within 7 '

days or submit a Special Report within 14 days of the event, this event is reportable pursuant to Technical Specification 6.9.2.

The process vent effluent path is continuously monitored by radiation monitor assembly RI-GW 178. On November 25,1989,1-RI-GW 178 began to alarm in the '

control room every 15 to 30 minutes. The Instrument Department was notified and RI-GW-178 was removed from service at 1627 hours0.0188 days <br />0.452 hours <br />0.00269 weeks <br />6.190735e-4 months <br /> on November 25,1989, to determine the cause of the alarm. Investigation revealed evidence of water in the gas i sampler chamber and smear results indicated that the check source had started to leach. Leaching of a check source contaminates the gas sampler chamber and Increases the activity.

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The water in the sample lines was a result of condensation due to the heat trace l system on the lines being inoperable. Upon receipt of the necessary materials, the heat trace system will be repaired. Following completion of the heat trace system  :

repair, the check source will be replaced, RI-GW 178 will be functionally tested and

returned to service, and the Action Statement will be cleared. Based on current l procurement and planning schedules, RI-GW-178 is scheduled to be returned to service by December 22,1989.

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This event posed no significant safety implications because the proplanned alternate t method of monitoring was established within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> as required by the Technical  !

Specifications. The Westinghouse Process Vent Radiation Monitors, which perform j the same automatic functions as Rl-GW-178, remained operable throughout this event. 1 Additionally, the Nuclear Research Corporation Radiation Monitors continued to  :

operate throughout this event as the Technical Specification required proplanned-  ;

alternate monitoring method on the process vent release path. l Very truly yours,  ;

s W. L ltewart -

Senior Vice President Nuclear oc: U.S. Nuclear Regulatory Commission Region ll  :

101 Marietta Street, N.W.

Suite 2900 i Atlanta, Georgia 30323  ;

Mr. J. L. Caldwell

• NRC Senior Resident inspector  ;

North Anna Power Station i

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