ML20062L607

Special Rept:On 930526,discovered That Triaxial Response Spectrum Analyzer (Trsa) Could Not Be Properly Calibr & Was Inoperable.Trsa Returned to Vendor on 930626 But Could Not Be Repaired Due to Lack of Spare Parts

ML20062L607
Person / Time
Site:	Limerick
Issue date:	12/23/1993
From:	Boyce R PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9401030229
Download: ML20062L607 (2)

Text

T.S. 3.3.7.2a-

%. T.S. 6.9.2 PHILADELPHIA ELECTRIC COMPANY LIMERICK GENERATING STATION P. O. BOX 2300  ;

SANATOGA, PA 19464-2300- December 23, 1993  ;

Docket Nos. 50-352 (215) 327-1200 EXT. 2000 50-353 License Nos. NPF-39 ROBERT W. BOYCE NPF-85 PUVT MANMER  ;

UMERICK GENERATING STATION U.S. Nuclear Regulatory Commission Attn: Document Control Desk washington, DC 20555 SURJECT: Limerick Generating Station, Units 1 and 2 Special Report for Inoperability of a Seismic Monitoring System Instrument for More Than 30 Days This Special Report is being submitted pursuant to the requirements of Limerick Generating Station (LGS), Unit .1 and Unit 2, Technical Specifications (TS) Section 6.9.2 as required by TS Section 3.3.7.2, " Seismic Monitoring Instrumentation." TS Section 3.3.7.2 requires that with one or more of the required Seismic Monitoring System (SMS) instruments inoperable for more than 30 days, a Special Report must be prepared and submitted within 10 days outlining the cause of the malfunction and the plans for restoring the instrument (s) to operable status, i

on May 26, 1993, with both units at 100% power, Instrumentation & Controls (I&C) technicians were performing Surveillance Test (ST) procedure ST-2-036-601-0, " Seismic Monitoring - Triaxial Response - Spectrum Analyzer Recorder ~

Calibration / Functional Test (XR-VA-109)." While procedure ST 036-601-0 was in progress, I&C personnel discovered that the Triaxial Response Spectrum Analyzer (TRSA) could not be properly calibrated and was inoperable. The TRSA is located in the Main Control Room (MCR) and would be used to playback and analyze the data-recorded by the SMS sensors following a seismic event. >

Troubleshooting identified that the problem most likely exists within the calibration circuit of the TRSA. The TRSA was-returned to the vendor on June 26, 1993, but could not be-repaired due to a lack of spare parts. j On December 13, 1993, during a review of a modification to upgrade the SMS, the system manager identified that a Special  :

Report for the' inoperable TRSA had not been submitted as' required by TS Action 3.3.7.2a. This Special Report is being submitted to  ;

satisfy the reporting requirement of the TS Action 3.3.7.2a and a  ;

Licensee Event Report is being prepared since the Special Report i was not submitted within the time limits specified in the TS .

h 9401030229 931223 y# kh PDR ADOCK 05000352 S PDR $- ,

t. a

L i U;S. Nuclear Regulatory. Commission ' December.23, 1993

,f 5 Document ControlLDesk Page 2 of 2 I

' Action and therefore is a' condition prohibited:by TS. )

J No seismic events have occurred since the TRSA was determined to be inoperable. Except for one accelerograph sensor, the' balance of the SMS which monitors the response of the plant to a seismic event was and remains operable to sense, i alarm, and record seismic data from a balance of 6 sensors. The inoperable sensor was reported to the NRC in a Special Report dated October 16, 1992 per the requirements:of TS Action 3.3.7.2a and is expected to be repaired during the next Unit'l refueling ,

outage expected to begin on January 28, 1994. The MCR operators have full capability of being alerted to a seismic event from the available seismic visual and audible annunciators located in the MCR. Operations personnel are trained to respond to these alarms and/or indications in accordance with Special Event _(SE) procedure SE-5, " Earthquake." The inoperable TRSA would affect 1 the onsite ability to analyze the recorded data following an carthquake. Offsite engineering support would be utilized in'the analysis of the seismic event and this analysis would not be performed immediately following the seismic event. Therefore, the actual and potential consequences of the condition are minimal.

A modification of the SMS is being planned to return the inoperable TRSA to an operable status, to increase the  ;

reliability of the entire system, and to upgrade the monitoring  ;

capabilities of the system. This modification entails  ;

replacement of all of the SMS equipment in the MCR with updated instrumentation. In addition, a TS Change Request is planned to be submitted to the NRC which will relocate the SMS instrument requirements from the TS to the LGS Updated Final Safety Analysis Report. The modification is planned toibe implemented'after the next Unit 1 refueling outage while both-Units are operating and within two months following NRC approval of the TS change. At the completion of the modification, the SMS will be' restored to-an operable status. ,

If you have are any questions or require additional information, please contact us, t

very truly-yours,.

( M -~1 -

DBN cc: T. T. Martin, Administrator Region I, USNRC N. S. Perry, USNRC Senior Resident Inspector, LGS l

-