ML062640435
| ML062640435 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 09/11/2006 |
| From: | Conicella N Constellation Energy Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML062640435 (2) | |
Text
Constellation Energy Nine Mile Point Nuclear Station P.O. Box 63 Lycoming, NY 13093 September 11, 2006 U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION:
SUBJECT:
Document Control Desk Nine Mile Point Nuclear Station Unit No. 1; Docket No. 50-220 Special Report: Inoperable Channel #12 of the Containment Hydrogen Monitoring System In accordance with Action 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 inoperability of Channel #12 of the Containment Hydrogen Monitoring (CHM) System.
Description of Event On August 28, 2006, at 0805 hours0.00932 days <br />0.224 hours <br />0.00133 weeks <br />3.063025e-4 months <br />, operators declared Channel #12 of the CHM System inoperable when the system was removed from service to support required surveillance testing.
At 1133 hours0.0131 days <br />0.315 hours <br />0.00187 weeks <br />4.311065e-4 months <br />, during the performance of the surveillance test, it was discovered that the high hydrogen and oxygen level annunciators and associated alarm lamps did not operate when required.
The redundant Channel #11 of the CHM System was verified to be operable prior to removal of Channel #12 from service.
Cause of Inoperabilit During performance of Channel #12 CHM System functional test, the high hydrogen and oxygen level annuciators failed to alarm in the control room as expected. The associated main system control hydrogen and oxygen alarm lamps also failed to illuminate as expected. The cause was determined to be a failed time delay relay.
Document Control Desk September 11, 2006 Page 2 Actions Taken The failed relay was replaced and post maintenance testing was completed satisfactorily.
Channel #12 of the CHM System was restored to operable status on August 29, 2006, at 1431 hours0.0166 days <br />0.398 hours <br />0.00237 weeks <br />5.444955e-4 months <br />.
Should you have any questions regarding this submittal, please contact M. H. Miller, Licensing Director, at (315) 349-1510.
Sincerely, Nicola F. Conicella Manager Operations NFC/RF/cld cc:
S. J. Collins, NRC Regional Administrator, Region I L. M. Cline, NRC Senior Resident Inspector