ML020580195
| ML020580195 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 02/08/2002 |
| From: | Montgomery B Constellation Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NMP1L 1641 | |
| Download: ML020580195 (2) | |
Text
P.O. Box 63 Lycoming, New York 13093 Constellation Nuclear Nine Mile Point Nuclear Station February 8, 2002 A Member of the NMP1L 1641 Constellation Energy Group U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 RE:
Nine Mile Point Unit 1 Docket No. 50-220 DPR-63
Subject:
Special Report, Channel #12 Suppression Chamber Water Level Indicator Inoperable Gentlemen:
In accordance with Action Statement 4.a of Nine Mile Point Unit 1 Technical Specification Table 3.6.11-2, Accident Monitoring Instrumentation Action Statements, Nine Mile Point Nuclear Station, LLC is submitting the following Special Report concerning the inoperability of Channel #12 Suppression Chamber Water Level indicator.
Description of Event On January 25, 2002 at 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br /> the operating crew declared the Channel #12 Suppression Chamber Water Level indicator inoperable after noting that the water level indicator was erratic and not trending as expected. The operating crew verified that the Channel #11 Suppression Chamber Water Level indicator was operable.
Cause of Event The cause of the Channel #12 Suppression Chamber Water Level indicator degraded response is ripple voltage on the output of the AC to DC power supply to the indicator. The power supply, PWRS-(1S12)24VDC, is a Bailey Type 765. The ripple voltage is attributed to the aging of the capacitors associated with the power supply.
I/V
Page 2 NMP1L 1641 A search of work history did not identify any previous failures of power supply PWRS-(iS12)24VDC.
Corrective Actions
- 1.
Power supply, PWRS-(lS12)24VDC, will be repaired by March 28, 2002.
- 2.
A Preventive Maintenance activity was established to routinely replace capacitors on power supply PWRS-(lS12)24VDC.
Very truly yours, ce
.Montg cry Gene al Manager Nuclear Engineering LAH/KLE/cld cc:
Mr. H. J. Miller, NRC Regional Administrator, Region I Mr. G. K. Hunegs, NRC Senior Resident Inspector Records Management