ML20209G817

Special Rept:On 860624,discovered Triaxial Response Spectrum Inoperable During Semiannual Surveillance Test. Cause Unknown.Analyzer Will Be Shipped to Mfg for Repairs. Related Correspondence

ML20209G817
Person / Time
Site:	Limerick
Issue date:	07/31/1986
From:	Leitch G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
CON-#386-227 OL, NUDOCS 8609150080
Download: ML20209G817 (4)

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RELATED PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET pg P.O. BOX 8699 PHILADELPHIA. PA.19101 July 31, 198 , A[g m me m ooo -

Alf;j3 Docket No,cy 352

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~ni:,inc; II:r;R f'ml; Dr. Thomas E. Murley, Administrator Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

SUBJECT:

Special Reporting Requirement for Inoperable Seismic Monitoring at Limerick Generating Station

REFERENCE:

Technical Specification 3.3.7.2 and 6.9.2

Dear Dr. Murley:

This special report is being submitted pursuant to the requirements of Limerick Technical Specifications 3.3.7.2 and

6. 9. 2 which s'. ate :

SEISMIC MONITORING INSTRUMENTATION:

3.3.7.2 The seismic monitoring instrumentation shown in table 3.3.7.2-1* shall be OPERABLE.

l APPLICABILITY: At all times.

ACTION:

a. With one or more of the above required seismic monitoring instruments inoperable for more than 30 days, prepare and submit a Special Report to the Commission pursuant to Specification 6.9.2 within the next 10 days outlining the cause of the malfunction and the plans for restoring the instrument (s) to OPERABLE status.

l 8609150080 860731 PDR ADOCK 05000352 S PDR

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D.r. Thomas E. Murley July 31, 1986 Page 2 SPECIAL REPORTS 6.9.2 Special reports shall be submitted to the Regional Administrator of the Regional Office of the NRC within the time period specified for each report.

DESCRIPTION OF EVENT:

On June 24, 1986 with the unit at power, the semi-annual surveillance test for the Triaxial Response Spectrum Analyzer (TRSA) was performed. The TRSA analyzes data from Triaxial Time-History Accelerographs and provides acceleration values for a range of frequencies (0-33.5 HZ). The surveillance test revealed that the unit was inoperable. The TRSA is a Model No. 505N1 manufactured by MRAD Corporation.

CONSEQUENCES OF THE EVENT:

The consequences of this condition are minimal. The control room will continue to receive notification of a seismic event because the control room annunciators receive signals from components of the seismic monitoring system which are operable. The function of the TRSA is to analyze the recorded accelerations from various plant locations and generate a peak acceleration versus frequency curve. With the TRSA inoperable, the acceleration data, which is recorded on magnetic tape, can be sent off-site for analysis by another TRSA.

CAUSE 0,P EVENT:

i The specific cause for the failure of the TRSA has not been determined. The investigation is continuing. A supplemental report describing the results of the investigation will be submitted by October 1, 1986.

CORRECTIVE ACTION:

The manufacturer of the TRSA was contacted and requested to l supply field support to assist instrumentation and control l

technicians in troubleshooting the device. However, due to personnel illness, no field representative was available. The TRSA is scheduled to be shipped off-site to the manufacturer to implement repairs.

! PREVIOUS SIMILAR OCCURRENCES:

A revised special report concerning inoperable seismic monitoring equipment (TRSA) was submitted on July 15, 1985. The cause of l

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Dr. Thomas E. Murley July 31, 1986 Page 3 the event was an inoperable " scale factor operational amplifier".

A voltage-to-frequency converter was also determined to be defective.

Should you require additional information, please do not hesitate to contact us.

Very truly yours,

. . Leitch Superintendent Nuclear Generation Division cc: E. M. Kelly, LGS Resident Site Inspector See Attached Service List '

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cc: Troy B. Conner, Jr. , Esq.

Benjamin H. Vogler, Esq.

Mr. Frank R. Romano Mr. Robert L. Anthony Ms. Maureen Mulligan Charles W. Elliott, Esq.

Barry M. Hartman, Esq.

Mr. Thomas Gerusky

+ Director, Penna. Emergency Management Agency Angus Love, Esq.

David Wersan, Esq.

Robert J. Sugarman, Esq.

Kathryn S. Lewis, Esq.

Spence W. Perry, Esq.

Jay M. Gutierrez, Esq.

Atomic Safety 4 Licensing Appeal Board Atomic Safety 4 Licensing Board Panel Docket 4 Service Section E. M. Kelly Timothy R. S. Campbell t

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