ML20207G267
| ML20207G267 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 03/01/1999 |
| From: | Rich Smith NIAGARA MOHAWK POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NMP1L-1413, NUDOCS 9903120037 | |
| Download: ML20207G267 (2) | |
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7 uiagaragmona.u-March 1, 1999 NMPIL 1413 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 Gentlemen:
In accordance with Nine Mile Point Unit 1 (NMP1) Technical Specification Table 3.6.11-1,
" Accident. 'onitoring Instrumentation," and associated Action Statement 4.a, Niagara Mohawk Power Corporation (NMPC) is submitting rhe following Special Report concerning the inoperability of ',he #12 Containment Hydrogen Monitoring System (HMS).
Desniotion of Event On February 15,1999, at 0550 hours0.00637 days <br />0.153 hours <br />9.093915e-4 weeks <br />2.09275e-4 months <br />, with the reactor mode switch in the "RUN" position during normal operations, NMP1 Operators declared the #12 HMS inoperable because flow switch FS-201.2-1495 failed to initiate an alarm for an indicated sample low fic,w condition.
Operators adjusted the sample flow rate to the required range, and then removed the #12 HMS from service to troubleshoot the flow sv/ itch.
Cause of Erttd NMP1 Maintenance personnel determined that the cause of the failure was a degraded encapsulated reed switch within flow switch FS-201.2-1495.
O NMP1 Maintenance personnel performed a review of the Deviation / Event Report and work convol databases and concluded that there have been no similar failures of flow switch FS-201.2-1495 or the #11 HMS flow switch, FS-201.2-1493.
The cause of the sample low flow condition has not yet been determined.
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b" 9903120037 990301 7 PDR ADOCK 050CO2204 S
PDR Nir.e Mile Point Nuclear Station, P0. Box 63,lycoming, New York 130934063 + 315.343.2110
- www.nimo.com
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Cometive Actions NMP1 Instrument and Control Technicians replaced flow switch FS-201.2-1495 and satisfactorily tested the switch on February 22,1999.
HMP1 Operators returned the #12 HMS to service at 1420 hours0.0164 days <br />0.394 hours <br />0.00235 weeks <br />5.4031e-4 months <br /> on February 22,1999.
NMPC will investigate the low flow condition and submit a supplement to this report when the cause has been determined.
1 Very truly yours, Robert G. Smith Plant Manager - NMP1 RGS/KLIJkap xc:
Regional Administrator, Region I Mr. Gordon K. Hunegs, Senior Resident Inspector Records Management I
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