ML20245B339

Special Rept:On 890303,seismic Monitoring Instruments Inoperable for More than 30 Days.Caused by Triaxial Accelerometer Cables Picking Up Electrical Noise Which Caused Spurious Alarms.Noise Filters Will Be Installed

ML20245B339
Person / Time
Site:	Peach Bottom
Issue date:	04/14/1989
From:	Danni Smith PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 8904260041
Download: ML20245B339 (2)

Text

-. ._

U CCh-II9-1405S

' /, ' ' PHILADELPHIA ELECTRIC COMPANY

• 813 PEACil BOTIDM ATOMIC POWER STATION L

R. D.1, Box 208 L %g Delta, Pennsylvania 17314

. rucn normne-rue rowra or excturmct (717) 456-7014 D. M. Smith l V)ce President April 14, 1989 Docket Nos.-50-277 50-278 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

SUBJECT:

Peach Bottom Atomic Power Station Special Report - Seismic Monitoring Instruments Inoperable for More Than Thirty Days

REFERENCE:

Technical Specifications (T.S.) 3.15.B Requirement for the Report This special report is being submitted pursuant to Peach Bottom T.S.

3.15.B. This T.S. requires that if one or more seismic monitoring instruments are inoperable for more than thirty days a special report is to be submitted within the next ten working days, outlining the cause of the malfunction and plans for restoring the instrument (s) to operable status.

Cause of the Instrumentation Being Inoperable On March 3, 1989, at approximately 3:22 a.m., the seismic monitoring system spuriously alarmed several times. The system was declared inoperable and a Maintenance Request Form was initiated to investigate and repair the problem. It was determined that the triaxial accelerometer cables were picking up electrical noise which caused the spurious alarms. Unit 2 was in cold shutdown and Unit 3 was in refuel at the time of the event.

Plan for Restoring the Instrumentation to Operable Status Noise filters recommended by the equipment veridor will be installed for ,

the triaxial accelerometer after receipt from the vendor. The filters have  !

been ordered and delivery is expected by April 30, 1989.

4 Sincerely, p

8904260041 890414 / l PDR ' ADOCK 05000277 S PDC

, '3 .Page 2 cc

J. T. Boettger, Public Service Electric & Gas T. M. Gerusky,. Commonwealth of Pennsylvania T. P. Johnson, USNRC Senior Resident Inspector T. E.-Magette, State of Maryland W.-T. Russell, Administrator, Region I, USNRC H. C. Schwemm, Atlantic Electric J. Urban Delmarva Power bec: J. A. Basilio/FDL - S10-1 E. J. Bradley - S23-1 Commitment Coordinator - S7-1 Correspondence Control Desk - NS-5 T. E. Cribbe - PB DAC - PB G. F. Daebeler - PB E. P. Fogarty - S7-1 J. F. Franz.- PB J. W. Gallagher - S25-1 D. R. Helwig - S7-1 G. A. Hunger - S7-1 S. J. Kowalski - S25-1 A. J. Marie - N2-1

'C. J. McDermott - S13-1 C. A. McNeill, Jr. - S26-1 T. 'Ryan - S10-1

.0. M. Smith - SM0-1 1

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