ML080230511
| ML080230511 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 01/11/2008 |
| From: | Belcher S Constellation Energy Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML080230511 (2) | |
Text
Sam L. Belcher P.O. Box 63 Plant General Manager Lycoming, New York 13093 315.349.5205 315.349.1321 Fax Constellation Energy-Nine Mile Point Nuclear Station January 11, 2008 U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION:
Document Control Desk
SUBJECT:
Nine Mile Point Nuclear Station Unit No. 1; Docket No. 50-220 Special Report: Inoperable Suppression Chamber Water Level Instrument In accordance with Action 4.a of Nine Mile Point Unit 1 (NMP1) Technical Specifications (TS) Table 3.6.11-2, "Accident Monitoring Instrumentation Action Statements" and TS Section 6.6.6.h, "Special Reports," Nine Mile Point Nuclear Station, LLC (NMPNS) is submitting the following Special Report concerning inoperability of Channel #12 of the Suppression Chamber Water Level Accident Monitoring instrumentation.
Description of Event On December 28, 2007, at 1253 hours0.0145 days <br />0.348 hours <br />0.00207 weeks <br />4.767665e-4 months <br />, operators declared-Channel #12:of the Suppression Chamber Water Level Accident Monitoring instrumentation (Level Transmitter LT-58-05) inoperable.
following surveillance testing/calibration. During surveillance activities, the transmitter was found out of calibration. Recalibration efforts were unsuccessful.
Redundant Suppression Chamber Water Level Transmitter Channel # 11 was operable.
Cause of Inoperability The cause for the Suppression Chamber Water Level Transmitter LT-58-05 inoperable condition was due to instrument drift and the inability to correct (raise) the instrument's zero elevation adjustment setpoint-beyond its existing lower than required value.
Actions Taken A Work Order was generated to troubleshoot and repair the failed instrument. Per the applicable Rosemount Transmitter instruction manual, technicians completed installation of a bias jumper wire on the transmitter's amplifier board, specifically intended to expand the instrument's zero adjustment.
limits. Following jumper installation, LT-58-05 recalibration was successfully completed including verifying proper instrument function repeatability. Control room operators returned Channel # 12 Suppression Chamber Water Level Transmitter LT-58-05 to an operable status on January 05, 2008 at 1044 hours0.0121 days <br />0.29 hours <br />0.00173 weeks <br />3.97242e-4 months <br />.
Document Control Desk January 11, 2008 Page 2 Should you have any questions regarding the information in this submittal, please contact T. F. Syrell, Licensing Director, at (315) 349-5219.
Very truly yours, Sam L. Belcher Plant General Manager SLB/GB cc:
NRC Regional Administrator, Region I NRC Senior Resident Inspector M. J. David, NRC Project Manager