ML20132G877

Special Rept 85-08:on 850814,during Storm,Free Field Strong Motion Accelerometer Inoperable.Caused by Voltage Surge When Lightning Struck Near Power Block.Instruments Returned to Vendor for Repairs

ML20132G877
Person / Time
Site:	Callaway
Issue date:	09/23/1985
From:	Miltenberger S UNION ELECTRIC CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
85-08, 85-8, ULNRC-1180, NUDOCS 8510010648
Download: ML20132G877 (3)

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'P/d i UNION ELECTRIC COMPANY

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1 .: CALLAWAY PLANT

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P. O. BOX .3 0 P ULTON. MO. 53 59 September 23, 1985 Mr. James G. Keppler Regional Administrator Office of Inspection & Enforcement U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 ULNRC-1180

Dear Mr. Keppler:

-DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 FACILITY OPERATINC LICENSE NPF-30 SPECIAL REPORT 85-08 INOPERABLE SEISMIC MONITORING INSTRUMENTATION The enclosed Special Report is submitted pursuant to Technical Specification 3.3.3.3 and 6.9.2 concerning the inoperable F: ee Field Seismic Monitor instrument.

S. E. Miltenberger Manager, Callaway Plant e

CDN/SEMe /drs l Enclosure

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cc: Distribution attached

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8510010648 850923

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W m-cc distribution for ULNRC-1180 Mr. iom Alexion Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop P-316 7920 Norfolk Avenue Bethesda, MD 20014 American Nuclear Insurers c/o Dottie Sherman, Library The Exchange Suite 245 270 Farmington Avenue Farmington, CT 06032 Records Center Institute of Nuclear Power Operations Suite 1500 1100 Circle 75 Parkway Atlanta, GA 30339 Mr. Nicholas A. Petrick Executive Director, SNUPPS 5 Choke Cherry Road Fockville, Maryland 20850 Mr. J. H. Smith Bechtel Power Corporation SNUPPS Project 15740 Shady Grove Road Gaithersburg, Maryland 20877-1454 NRC Resident Inspector D. F. Schnell J. F. McLaughlin J. E. Davis (Z40LER)

D. W. Capone /R. P. Wendling F. D. Field R. L. Powers A. C. Passwater/D. E. Shafer/D. J. Walker G. A. Hughes W. R. Robinson (QA Record)

J. M. Price C. D. Naslund R. A. McAleenan S. L. Auston (470)(NSRB)

Merlin Williams, Wolf Creek SEM Chrono 3456-0021.6 3456-0260 Z40ULNRC G56.37 N. Date

SPECIAL REPORT 85-08 INOPERABLE SEISMIC MONITORING INSTRUMENTATION This report is being generated in accordance with Technical Specification (T/S) 3.3.3.3 Action a.'which states "with one or more of the above 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."

During an electrical storm, on 8/14/85 at 0510 CDT, a lightning strike occurred near the power block. This induced a voltage surge in the power cable to the Free Field Strong Motion Accelerometer which is one of six triaxial accelerometers required per T/S 3.3.3.3. As a result lof this. voltage surge, the electronics in the instrument were damaged. The electrical setpoint of the instrument was exceeded thus causing Seismic Monitoring Panel (SG058) alarms to activate. The Free Field instrument was declared inoperable at 0510 CDT thus placing the plant in T/S 3.3.3.3 Action a.

A Work Request was initiated to troubleshoot the Free Field instrument on 8/14/85. No spare instrument was readily available as the vendor (Terra Technology Inc.) was repairing the spare instrument offsite due to a previous failure. Upon receipt of the spare instrument back from the vendor on 9/9/85, the Free Field instrument replacement commenced. The spare instrument then failed to bench check with the cause of the failure being unknown. Therefore, both the installed and spare Free Field instruments were returned to the vendor on 9/13/85 for

-repairs.

When the instruments are received on site, one will be installed to restore Free Field monitoring capability. Expected date of return to OPERABLE status is 10/25/85.

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