ML20140F438

Special Rept 85-008:on 850415,containment Base Slab Seismic Monitor Declared Inoperable Due to Failed Power Supply.Cause Unknown.New Power Supply Ordered.Temporary Power Supply Installed

ML20140F438
Person / Time
Site:	Wolf Creek
Issue date:	06/24/1985
From:	Koester G KANSAS GAS & ELECTRIC CO.
To:	Martin R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
85-008, 85-8, KMLNRC-85-163, NUDOCS 8507120073
Download: ML20140F438 (2)

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KANSAS GAS AND ELECTRIC COMPANY THE: ELECTf*C CryapANy

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Mr. R.D. Martin, Regional Administrator U.S. Nuclear Regulatory Conmission Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 KMLNRC 85-163 Re: Docket No. STN 50-482 Subj: Special Report 85-008

Dear Mr. Martin:

The enclosed Special Report is submitted pursuant to Technical Specifications 6.9.2 and 3.3.3.3.

If you have any questions concerning this natter, please contact me or Mr. Otto Maynard of rny staff.

Yours very truly, h k 3 Glenn L. Koester Vice President - Nuclear Gm: dab Enclosure xc: IO'Connor (2), w/a JCunmins, w/a 8507120073 050624 PDR ADOCK 05000482 S PDR

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201 N. Market - Wichita, Kansas - Mail Address: RO. Box 208 I Wichita. Kansas 67201 - Telephone: Area Code (316) 2616451

SPECIAL REPORr 85-008 Seismic Monitor Inoperability On May 15, 1985, a seismic monitoring instrument was declared inoperable.

his Special Report is being sutmitted pursuant to Technical Specifications 3.3.3.3 and 6.9.2 due to the seimic monitoring instrumentation remainiry out of service for more than 30 days.

On May 14, 1985, at approximately 2016 CDP, the annunciators 98D and 98E, indicating "Operatirg Basis Earthquake" and " Seismic Recorder On", alarmed on the Main Control Board. We Watch Station Operators were dispatched to exmine the Ergineered Safety Features (ESP) omponents for signs of d mage. In the meantime, an unsuccessful attempt was made to clear the alarms.

We Instrmentation and Control group (I&C) was contacted to investigate arrl retrieve data frm the seismic recorders. We exmination of ESP cmponents revealed no evidence of dmage to plant equipment or occurrence of a seismic event. At approximately 0315 Cur on May 15, 1985, the Contaiment Base Slab seismic monitor was declared inoperable due to the preliminary results of I&C's investigation and due to the fact that there was no evidence that a seismic event had actually occurred.

A failed power supply in the seismic monitoring system was subsequently discovered and replaced with a new power supply. We replacement power supply also failed due to its inadvertent operation prior to completion of installation.

A temporary power supply was installed in place of the failed power supplies in order to verify the operability of the system. Durity the process of verifying operability, a failure was discovered in free-field accelercmeter SG-AR01.

A Work Request has been initiated to uncover the free-field accelermeter, which is buried approximately eight (8) feet deep, and determine the cause of its failure.

We root cause of the failure of the power supply that initially rendered the Contairment Base Slab seismic nonitor inoperable is unknown at this time. Ilowever, a new power supply to replace the failed power supplies has been ordered arx3 will be installed upon receipt. Durirg the interim, a temporary power supply has been installed to make the seismic monitoring system functional.

Upon completion of the investigation into the failure of SG-AR01, the surveillance procedure STS IC-894, " Channel Calibration Triax Time History and Response Spectra Recording System" will be performed to verify the operability of the seismic monitoring instrm entation.

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