ML19309D751

Ro:On 800225,two Frequencies on Peak Shock Annunciator Sys Actuated Visual Alarms.Cause Unknown.Problem w/70% (OBE) Visual Alarms May Have Been Caused by Reed Switches or Alarm Circuitry.Investigation Is Continuing

ML19309D751
Person / Time
Site:	Beaver Valley
Issue date:	04/03/1980
From:	Werling J DUQUESNE LIGHT CO.
To:
References
BVPS:JAW:827, NUDOCS 8004110385
Download: ML19309D751 (2)

Text

-.

~

. .

, *na t ' 0 .'s , '

r . :e

'

RA } .M dt

• s, ?'f %

(412) 456 6000 e s ,. ._,-.

PittsburgN, Pennsylvama DUQUESNE LIGHT COMPANY u2ts Beaver Valley Power Station Post Office Box 4 Shippingport, PA 15077 April 3, 1980 BVPS: JAW:827 Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Special Report Mr. B. H. Grier, Director of Regulation United States Nuclear Regulatory Commission Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406

Dear Mr. Grier:

In accordance with BVPS Technical Specification 3.3.3.3, Seismic Instrumentation, the following special report is submitted.

On February 25, 1980, two frequencies on the Peak Shock Annunciator System actuated their visual alarms. After checking the Strong Motion Accelerograph seismic t 3ger, we determined that no actual seismic event had occurred. The frequencies that annunciated were the 20.2 Hz 70% and 100% Operational Basis Earthquake (OBE) signals and the 25.4 Hz 70% (OBE) signal. Both were for the north-south direction.

Prior to troubleshooting the system, the 100% (OBE) alarm was reset and the visual alarm cleared..,The problem with the 70% (OBE) visual alarms has been traced to the transmitters in containment and is thought to be caused by either the reed switches or by the alarm circuitry.

Maintenance personnel are continuing their investigation. A supplemental report will be sent to you when a more definitive solution to this problem is found.

Very truly yours, 1

.A/f/

J. A. Werling w 1 Superinten0at '

8004110'385I

. _ __ _ _ _ _ _ _

• m .

Hr. B. H. Crier April 3, 1980 BVPS: JAW:827 Page 2 cc: Director Of Management & Program Analysis w#

United States Nuclear Regulatory Commission Washington, D. C. 20555 ,

!

D. L. Wigginton, BVPS Licensing Project Manager United States Nuclear Regulatory Commission Washington, D. C. 20555 D. A. Beckman, Nuclear Regulatory Commission, BVPS Site Inspector

, G. A. Olson, Secretary, Prime Movers Committee - EEI i

,

i

?

I l

l l

,

..

.

'

B e

- a one y

- . - ,