ML20028H692
| ML20028H692 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 01/22/1991 |
| From: | Bailey J WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 91-001, 91-1, NO-91-0019, NO-91-19, NUDOCS 9101280156 | |
| Download: ML20028H692 (2) | |
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WMF CREEK NUCLEAR OPERATING CORPORATION John A Bailey Vee PsonHhwet Nuclear Operallons January 22, 1991 NO 91-0019 U. S. Nuclect Regulatory Commission ATTH:
Document Control Desk Hall Station P1-137 Washington, D. C.
20555
Subject:
Docket No. 50-482:
Special Report 91-001 The attached Special Report is being submitted in accordance with Technical Specification 3.3.3.4 concerning the inoperability of the 10 and 60 meter elevation wind speed indicators for the meteorological tow 4r.
Very truly yours, j
k John A. Bailey Vice President Nuclear Operations JABlaem Attachment cci A. T. Howell (N"C), w/a R. D. Hartin (NRC), w/a D. V. Pickett (NRC), w/a M. E. Skow (NRC), w/a 0101280156 910122 PDR ADOC t O'!.OOO482 5
PDR RO Box 411/ Durhngton, KS 66839 / Phone:(316) 364 8831 An Eouet oppartunny Employer Mi>HCNET gg i%~
4 s.
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Special Report 91-001 Inoperable Meteornlogical Tower Instrumentation On January 5, 1991, at opproximately 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br />, the 10 and 60 meter elevation wind speed indicators for the meteorological tower were declared inoperable. Because this 4
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inoperability extended beyond a 7 day period, this Special Report is being submitted pursuant to Technical Specifications 3.3.3.4 and 6.9.2.
i On January 5,
- 1991, at approximately 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br />, it was
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discovered that the 10 and 60 meter elevation wind speed indicators for the meteorological tower.were malfunctioning.
3 The Control Room operators concluded that the malfunction was caused ~by inclement weather. During normal operation, the indicators are affixed to the tower by use of a bearing assembly, which allows free radial movement.
Based on past experience, freezing precipitation causes the bearings to freeze to their housing, - thereby restricting free movement of
' the indicators. The indicators were declared inoperable, and entry was made into - Technical Specification 3.3.3.4, Action a,
which requires that the instrumentation be returned to service within 7 days, or that a Special Report be submitted within the following 10 days.
Below average temperatures continued until January 13, 1991, at which time temperatures climbed above the freezing point.
At approximately 1210 hours0.014 days <br />0.336 hours <br />0.002 weeks <br />4.60405e-4 months <br />, the indicators thawed, and the instrumentat-lon was returned to service at that time. On January 14,
- 1991, Instrumentation and Control personnel visually inspected the wind speed indicators to confirm proper operation.
This is the first event in which the wind speed indicators were-inoperable for more than 7 days because of inclement weather. However, freezing of the ' instrumentation for brief periods of time has occurred previously. In order to prevent weather-related malfunctions of this instrumentation, a
design change-.has been developed to provide a cover over the bearing' housings to prevent precipitation from collecting in the bearing housings. It is planned to install this weather i
- shielding during the next semi-annual channel calibration, currently scheduled to begin April 21, 1991.
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