ML20132D370

Revised Special Rept Re Cause & Corrective Actions for Inoperable Seismic Monitoring Instrumentation.On 850626,test Results of Triaxial Response Spectrum Analyzer Satisfactory. Related Correspondence

ML20132D370
Person / Time
Site:	Limerick
Issue date:	07/15/1985
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
CON-#385-890 OL, NUDOCS 8509300154
Download: ML20132D370 (4)

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~ ^ RE. LATED COMRt bM#M -g PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET .b3 P.O. BOX 8699 22 4// lg7 PHILADELPHI A. PA.19101 c 0' -

saisi e4i.4ooo Bh hhk July 15, 1985 Docket No. 50-352 6L License No. NPF-27 Dr. Thomas E. Murley, Administrator Region I U.S. Nuclear Regulatory Connission 631 Park Avenue I King of Prussia,.PA 19406 SURJECT: Special Reporting Requirement for Inoperable Seismic Monitoring at

Limerick Generating Station Follow-Up Report

REFERENCE:

Technical Specification 3.3.7.2 and 6.9.2

Dear Dr. Murley:

This revision to a special report of an inoperable seismic monitoring system, submitted June 12, 1985 amplifies the corrective action and cause of event. Revisions are shown'with a vertical bar ir. the margin. Special reports on of this nature are submitted pursuant to the requirements of Technical Specification 3.3.7.2 and- 6.9.2 which state 3.3.7.2 The seismic monitoring instrumentation shown in Table 3..? .7.2-l* shall be OPERABLE.

. 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. ,

8509300154 850715 PDR ADOCK 05000352 s PDR

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9 D.rs Thomas;E.;Murl'y e July 15, 1985 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 I time period specified for each report.

j DESCRIPTION OF EVENT:

On May 1, 1985, with the unit in cold shutdown, the surveillance test for the Triaxial Response Spectrum Analyzer I (Model No. 505N1 MRAD Corp.; TRSA)'was performed. The.TRSA j analyzes data and provides acceleration values for a range of

! frequencies (0-33.5 HZ). The ST for the TRSA revealed that

! acceptable limits for the specific acceleration input-of a

! negative 0.05g could not be met; however, all other j acceleration inputs were within acceptable limits.

CAUSE OF CVENT:

i The specific cause of failure was originally undetermined. A l manufacturer's representative was contracted to investigate the problem. It was determined that the " scale factor operational amplifier" on the analyzer board was inoperable.

' This component receives an' input signal from the magnetic 2

tape data and generates a proportional signal for the

microprocessor to analyze.

A second problem was identified which required that the

analyzer be taken off site for repairs. A voltage to frequency converter in the. internal clock was also defective.

The internal clock in used in storing data.

CONSEQUENCES OF EVENT:

Triaxial accelerameters are used to collect seismic data and alert the oporatorn to the occurrence of a possible seismic i event.. The TRSA is used to analyze the data _which is l

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collected at'various locations throughout the plant. With the TRSA inoperable the data can be sent off-site for analysis. 1Nie remainder of the seismic monitoring system, including annuciators and accelerameters were operable; therefore, the. consequences of this event were minimal.

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D r .:~ T h o m a.'s : E . M u r l e y July 15, 1985 7 '

Page 3

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CORRECTIVE ACTION:

A field representative from'.the manufacture of the TRSA arrived on-site on June 12,-1985 to address this problem and effect repairs.

The manufacturer's representative repaired the " scale factor operational amplifier" on site and the TRSA was functionally tested (ST. 2.036.601-0). The test results were not satisfactory.~and the analyzer was taken off site for repairs to the voltage to frequency converter in the internal clock.

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On June 26, 1985, the functional test was satisfactory completed and.the TRSA was declared operable.

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

Very truly yours,

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.i.nfu W. T. Ullrich Superintendent Nuclear Generation Division cc E. M. Kelly, LGS Senior Site Inspector See Attached Service List

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cc: Judge Helen F. Hoyt Judge Jerry Harbour Judge Richard F.. Cole Troy B. Conner, Jr., Esq.

Ann P. Hodgdon, Esq.

Mr. Frank R. Romano Mr. Robert L. Anthony Ms. Phyllis Zitzer Charles W. Elliott, Esq.

Zori G. Ferkin, 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 & Licensing Appeal Board Atomic Safety & Licensing Board Panel Docket & Service Section (3 Copies)

E. M. Kelly Timothy R. S. Campbell July 3, 1985 D