NL-09-148, Report on Inoperable Post Accident Monitoring Instrument Neutron Source Range
| ML093210514 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 11/05/2009 |
| From: | Robert Walpole Entergy Corp |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-09-148 | |
| Download: ML093210514 (2) | |
Text
Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, N.Y. 10511-0249 Tel (914) 734-6700 NL-09-148 November 5, 2009 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Report on Inoperable Post Accident Monitoring Instrument Neutron Source Range Detector N-39 Indian Point Unit 3 Docket No. 50-286 License No. DPR-64
Dear Sir or Madam:
The purpose of this letter is to submit a report pursuant to Technical Specification (TS) 5.6.7, in accordance with the action required by TS 3.3.3, "Post Accident Monitoring (PAM)
Instrumentation," Condition B.1 which requires the initiation of the actions of TS 5.6.7 immediately upon failure to restore an inoperable channel to operable within the required completion time of 30 days. Pursuant to TS 5.6.7, the report is to outline the alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrument to operable status.
PAM instrument N-39 is required to be operable in Modes 1, 2, and 3 by TS 3.3.3, Table 3.3.3-1, Function 1 "Neutron Flux." On October 14, 2009, during troubleshooting for failure to read within 10% of current power, the neutron source range detector N-38 internal power supply was discovered to be degraded and N-38 was declared inoperable at 15:00 hours. The time of inoperability was back dated to September 24, 2009, at 18:00 hours, which was the original time N-38 was first discovered to have discrepancies with its readout. Neutron source range detector N-38 and N-39 are credited as a PAM instruments in TS 3.3.3. N-38 is credited as a remote shutdown instrument in TS 3.3.4, and as an Appendix R Alternate Safe Shutdown instrument per Technical Requirements Manual (TRM) 3.3.D. Because TRM 3.3.D has a 30 day shutdown TRO and the power supply availability could not at the time meet the TRO, a decision was made to swap the power supply from detector N-39 which.did not have a shutdown action associated with it. On October 15, 2009, the power supply swap was completed and source range detector N-39 was declared inoperable. TS 3.3.3 Condition A required completion time to restore the channel to operable is 30 days. On October 24, 2009, source range detector N-39 was not returned to operable and TS 3.3 Condition B entered. An aggressive search found an overseas supplier that expedited shipment of the applicable power supply which arrived at Indian Point on November 2, 2009. Planning has scheduled the installation of the power supply on November 9, 2009.
S-, 00
NL-09-148 Docket No. 50-286 Page 2 of 2 The alternate method of monitoring neutron source range for the PAM function is neutron source range detector N-38. The degraded power supply condition was recorded as a condition report (CR) in the Indian Point Energy Center Corrective Action Program. The CR will include an evaluation of the cause of the event and any necessary corrective actions.
There are no new commitments being made in this submittal.
If you have any questions or require additional information, please contact Mr. Robert Walpole, Licensing Manager, at 914-734-6710.
Sincerely, Mr. Robert Walpole Licensing Manager Indian Point Energy Center cc:
Mr. John P. Boska, Senior Project Manager, NRC NRR Mr. Samuel J. Collins, Regional Administrator, NRC Region 1 NRC Resident Inspector, IP2 Mr. Paul Eddy, New York State Dept. of Public Service