ML20155J169

Suppl 1 to Special Rept 85-011 Re Inoperable Loose Part Detection Sys Channel.On 850912,Channel 10 of Loose Part Detection Sys Declared Inoperable.Caused by Faulty Preamplifier Charge Converter.Converter Replaced

ML20155J169
Person / Time
Site:	Wolf Creek
Issue date:	10/17/1988
From:	Withers B WOLF CREEK NUCLEAR OPERATING CORP.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
85-011, 85-11, WM-88-0264, WM-88-264, NUDOCS 8810250313
Download: ML20155J169 (2)

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6 W4pLF CREEKNUCLEAR OPERATING CORPORATION Bart D. WWws Preeoent and CW EsecuWre Omcer October 17, 1988 WM 88-0264 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P!-137 Washington D.C. 20555 St.bj ec t : Docket No. 50-482: Special Report 85-011, supplement 1 Gentlemen The attached supplemental report is being submitted pursuant to Technical Specifications 3.3.3.9 and 6.9.2. This report concerns an inoperable Loose-Part Detection System channel.

If you have any questions concerning this matter, please contact me or Mr. O, L. Mayna ' of my staf f.

Very truly yours, v

Bart D. Withers President and Chief Executive Officer BDW/11k Attachment ec: B. L. Bartlett (NRC), w/a D. D. Chamberlain (NRC), w/a

2. D. Martin (NRC), w/a l

D. V. Pickett (F'tC), w/a (2) 8810250313 881017 l PDR ADOCK 05000482 '

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, . Attachment to WM 88-0264 SPtCIAL RFFORF 85-011, Steptament 1 l

l ILOSE-PARr DUrfrr10N SYSrtF. INOPERABEE OIANNEL Special Report 85-011 (reference KMIRic 85-239, dated October 22, 1985) was subnitted pursuant to Technical Specification 6.9.2 and Technical Specificaticn 3.3 3.9, Acticn Statement a, conceming a Icose-Part Detecticn Systesu Channel which had been inoperable for nore usan thirty days.

On Septenber 12, 1985, at vproximately 1625 GP, Channel 10 of the im Part Detectics, System was declared inoperable. 'Ihis failure was identified I during the periormance of surveillance procedure STS-IC-830, "Vibration ard Icose Parts Mcnitor Analog Oannel Operational Test", and was irdicated by the absence of backgrourd noise when Channel 10 was soleicted on the Audio Mmitor. 'Ihe Channel 10 acceleroneter is located on the lower sugport flange of Eteen Generator "C".

During troubleslooting efforts at the time, technicians verified that no cable ground fault exista3. A ccuparison of chieneter readings in the tenninal box just tretream of the dannel 10 accelercrieter with the readings of the Channel 9 acceleroneter, which is 120 degcees t.way fran Channel 10 cn the same supporting flange, fcud to significant differences. 'the technicians also attenptal to inspect the acceleroneter enclosure, but due to the plant being at nonnal opetating tenperature, were unable to perfona an inspection beycn1 the insulation on the acceleroneter.

A mentionsi in the previously subnitted resort, further investigations concerning the Channel 10 accelercmeter malfunction were in progress. In late February,1986, while the tnit was in Hot Standby, a faulty prennplifier chstge ccnverter war identified in the Channel 10 acceleroneter cirt:uttry. 'Ihis charge cxnverte was replaced, an1 the Channel 10 acceleramter was testal satisfactorily an! restored to operable ntatus cn February 27, 1986.

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