ML20198M357
| ML20198M357 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 12/23/1998 |
| From: | Rich Smith NIAGARA MOHAWK POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NMP1L-1392, NUDOCS 9901050318 | |
| Download: ML20198M357 (2) | |
Text
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NiagarahMohawk'
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December 23, 1998 NMPIL 1392 U. S. Nuclear Regulatory Commission Attn: Document Control Desk j
Washington, DC 20555 RE:
Nine Mile Point Unit 1 Docket No. 50-220 DPR-63
Subject:
Special Report Gentlemen:
\\
l In accordance with Nine Mile Point Unit 1 (NMPI) Technical Specification (TS) Table i
3.6.11-2, " Accident Monitoring Instrumentation," Action Statement 4.b.2, Niagara Mohawk Power Corporation (NMPC) is submitting the following Special Report concerning the g
inoperability of both #11 and #12 Containment Hydrogen Monitoring Systems (HMS).
1 (j Desedntion af Event On December 10,1998, at approximately 0630 hours0.00729 days <br />0.175 hours <br />0.00104 weeks <br />2.39715e-4 months <br />, with the reactor mode switch e the
- b9 "RUN" position during normal operation, NMP1 operators declared the #11 HMS inoperable due to the failure of the control room chart recorder. At the time, #12 HMS remained out of service as described in a Special Report (NMPIL 1368) dated October 12,1998. On December 11,1998, operators returned #12 HMS after successful post-maintenance testing.
On December 17,1998, operators returned #11 HMS to service following successful post-maintenance testing.
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ram of Event Maintenance personnel determined the cause of the #11 HMS recorder failure to be a failed inverter board in the power supply circuitry of the recorder due to component aging.
9901050318 981225~
DR ADOCK.0 0
Lycoming. New York 13093-0063
- 315.343.2110
- www.nimo.com
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Page 2 Corrwelive Arrinns Maintenance personnel replaced the failed inverter board, successfully tested the recorder, and returned it to service.
I In accordance with TS Table 3.6.11-2 Action 4b, chemistry personnel obtained grab samples during the period when both #11 HMS and #12 HMS were out of service.
l Very truly yours, l
Ah Robert G. Smith Plant Manager - NMPl RGS/KLidkap xc:
Mr. H. J. Miller, Regional Administrator, Region I Mr. G. K. Hunegs, Senior Resident Inspector Records Management 1
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