ML042040300

Special Report, Channel #12 of the Containment Hydrogen Monitoring System Inoperable for Nine Mile Point Unit 1

ML042040300
Person / Time
Site:	Nine Mile Point
Issue date:	07/12/2004
From:	O'Connor T Constellation Energy Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NMP1L 1851
Download: ML042040300 (2)

Text

.Constellation Energy P.O. Box 63 Nine Mile Point Nuclear Station Lycoming, New York 13093 July 12, 2004 NMP1L 1851 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

Nine Mile Point Unit I

_ _. _ _- _ - _Docket No. 50-220 __ _ _

License No. DPR-63 Special Report, Channel #12 of the Containment Hydrogen Monitoring System Inoperable Gentlemen:

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.

Descriptionof Event On June 28, 2004, at 1311 hours0.0152 days <br />0.364 hours <br />0.00217 weeks <br />4.988355e-4 months <br />, Channel #12 of the C1M System was declared inoperable when the system was removed from service to support required surveillance testing. At approximately 1604 hours0.0186 days <br />0.446 hours <br />0.00265 weeks <br />6.10322e-4 months <br /> during the performance of the surveillance test, it was discovered that the hydrogen sensor failed to generate alarms when required during testing.

The redundant Channel #11 was verified to be in service prior to removal of Channel #12 from service for testing.

Cause of Event During performance of Channel #12 CHM System functional test, the high hydrogen level annunciator failed to alarm in the control room as expected. The associated main system control hydrogen alarm ramp also failed to illuminate as expected. The cause was determined to be a failed time delay relay.

.t II NMP1L 1851 Page 2 CorrectiveActions The relay was replaced and post maintenance testing was completed. Channel 412 of the CHM System was restored to operable on July 07, 2004, at approximately 1440 hours0.0167 days <br />0.4 hours <br />0.00238 weeks <br />5.4792e-4 months <br />.

General Manager TJO/JTC/jm cc: Mr. H. J. Miller, NRC Regional Administrator, Region I Mr. G. K. Hunegs, NRC Senior Resident Inspector