ML061950391

Post Accident Monitoring Instrumentation Report: Division 2 of the Containment Monitoring System Inoperable

ML061950391
Person / Time
Site:	Nine Mile Point
Issue date:	07/05/2006
From:	Hutton J Constellation Energy Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML061950391 (2)

Text

Constellation Energy P.O. Box 63 Lycoming, NY 13093 Nine Mile Point Nuclear Station July 5, 2006 U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION: Document Control Desk

SUBJECT:

Nine Mile Point Nuclear Station Unit No. 2; Docket No. 50-410 Post Accident Monitoring Instrumentation Report:

Division 2 of the Containment Monitoring System Inoperable In accordance with Action B.1 of Nine Mile Point Unit 2 Technical Specification 3.3.3.1, "Post Accident Monitoring (PAM) Instrumentation," Nine Mile Point Nuclear Station, LLC, is submitting the following PAM Instrumentation Report concerning inoperability of Division 2 of the Containment Monitoring System (CMS).

PreplannedAlternate Monitorin' Method Collecting and analyzing grab samples from the drywell in accordance with the applicable surveillance procedure is the preplanned alternate monitoring method at Nine Mile Point Unit 2.

However, Division 1 of the CMS was available and placed in a protected state to assure availability of the redundant channel.

Cause of Inoperabilitv On May 22, 2006, operators identified a failed circuit which supplies heat trace power to the drywell sample line. Due to a procedure deficiency, the component was misidentified in the work management process causing the shift manager to incorrectly determine the operability of Division 2 of the CMS. On June 17, 2006, during a review of routine rounds comments, operators properly identified the failed component, which rendered Division 2 of the CMS inoperable. Division 2 of the CMS was subsequently declared inoperable as of 0700 on May 22, 2006.

Troubleshooting determined that a temperature detector (TD) in the degraded circuit was damaged. The failure of the TD prevented the heating circuit from keeping the drywell supply line warm, which could result in condensate formation in the line and inability to monitor containment atmosphere.

Document Control Desk July 5, 2006 Page 2 Actions Taken TD was replaced, post maintenance testing was performed satisfactorily and Division 2 of the CMS was restored to operable status on June 21, 2006, at 1053 hours0.0122 days <br />0.293 hours <br />0.00174 weeks <br />4.006665e-4 months <br />. The component misidentification was entered in the corrective action program and the associated procedure deficiency was corrected.

Should you have any questions regarding this submittal, please contact M. H. Miller, Licensing Director, at (315) 349-1510.

Sincerely, lames-A. Hutton Plant General Manager JAH/RF/sac cc: S. J. Collins, NRC Regional Administrator, Region I L. M. Cline, NRC Senior Resident Inspector