NL-11-016, Revised Report on Inoperable Main Steam Line Radiation Monitor
| ML110550158 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 02/16/2011 |
| From: | Robert Walpole Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-11-016 | |
| Download: ML110550158 (2) | |
Text
~'Entergy Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, N.Y. 10511-0249 Tel (914) 734-6700 Robert Walpole Licensing Manager 914-734-6710 February 16, 2011 NL-11-016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
SUBJECT:
REFERENCE:
Revised Report on Inoperable Main Steam Line Radiation Monitor Indian Point Unit Number 3 Docket No. 50-286 License No. DPR-64 Entergy Letter NL-1 1-009 to NRC regarding Report on Inoperable Main Steam Line Radiation Monitor dated January 25, 2011.
Dear Sir or Madam:
The purpose of this letter is to update a report submitted in the referenced letter pursuant to Technical Specification (TS) 5.6.7. One radiation monitor channel per main steam line is required by TS 3.3.3, Table 3.3.3-1, item 22. Radiation monitor R-62D was declared inoperable on December 13, 2010 at about 1115 hours0.0129 days <br />0.31 hours <br />0.00184 weeks <br />4.242575e-4 months <br />. TS 3.3.3, Condition A requires the radiation monitor to be fixed within 30 days and if this completion time is not met, to submit a report to NRC pursuant to TS 5.6.7 that outlines the alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrument to operable status. This report, in the referenced letter, is being updated to reflect changes to the cause of inoperability and the schedule for restoring the instrument. It also corrects R45 to R1 5.
" Alternate method of monitoring The primary alternate method of monitoring for an out of service Steam Line Radiation Monitor channel is the Condenser Air Ejector Gas monitor R1 5 and the Steam Generator Blowdown monitor R19.
Cause R-62D detector failed while in use with a high voltage power supply failure. After successfully bench testing the replacement power supply the radiation monitor was frJ76K~
NL-1 1-016 Docket 50-286 Page 2 of 2 reconnected. The high voltage power supply failed again. Further investigation determined that there was an intermittent short inside the field side connector at the steam line detector enclosure. This short only manifested itself when the detector was connected via this connector and installed, thus subjecting it to small vibrations that caused the short to occur.
When tested alone, the short was not initially seen and only found during a subsequent 500v Megger test after the last power supply failure.
Plans and schedule for restoring After R-62D failed, test work on the monitor commenced the week of December 27, 2010. At that time, the failed high voltage power supply was discovered. When the power supply was replaced it failed again. An evaluation identified a short in the detector that the initial troubleshooting had not identified. Engineering was contacted on Friday, January 7, 2011 to discuss the. power supply issue and to provide assistance in locating a new detector. A new detector was located on January 10, 2011. Scaffold requests were generated and the detector and power supply were replaced. During the replacement an intermittent short was found on the field side connector. A new cable assembly was ordered and is expected to arrive on site on February 18, 2011. After calibration, installation and testing the channel will be put back in service. Estimated completion is March 4, 2011.
If you have any questions or require additional information, please contact Mr. Robert Walpole, Licensing Manager.
Sincerely, RW/sp cc:
Mr. John P. Boska, Senior Project Manager, NRC NRR Mr. William M. Dean, Regional Administrator, NRC Region I NRC Senior Resident Inspectors Office Mr. Francis J. Murray, Jr., President and CEO, NYSERDA Mr. Paul Eddy, New York State Dept. of Public Service