05000286/LER-2010-001, Regarding SSFF and TS Violation for an Inoperable RCS Wide Range Temperature Cold Leg Instrument TE-413B Credited for TS 3.3.4 Remote Shutdown
| ML101300069 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 04/30/2010 |
| From: | Joseph E Pollock Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-10-032 LER 10-001-00 | |
| Download: ML101300069 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor |
| 2862010001R00 - NRC Website | |
text
_ Entergy Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, N.Y. 10511-0249 Tel (914) 734-6700 J. E. Pollock Site Vice President NL-10-032 April 30, 2010 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop O-P1-17 Washington, D.C. 20555-0001
SUBJECT:
Licensee Event Report # 2010-001-00, "SSFF and TS Violation for an Inoperable RCS Wide Range Temperature Cold Leg Instrument TE-413B Credited for TS 3.3.4 Remote Shutdown" Indian Point Unit No. 3 Docket No. 50-286 DPR-64
Dear Sir or Madam:
Pursuant to 10 CFR 50.73(a)(1), Entergy Nuclear Operations Inc. (ENO) hereby provides Licensee Event Report (LER) 2010-001-00. The attached LER identifies an event where a remote shutdown instrument was found to be inoperable, which is reportable under 10 CFR 50.73(a)(2)(i)(B) as operation outside the Technical Specifications and 10 CFR 50.73(a)(2)(v)(A) as a safety system functional failure. This condition was recorded in the Entergy Corrective Action Program as Condition Report CR-IP3-2009-04823.
There are no new commitments identified in this letter. Should you have any questions regarding this submittal, please contact Mr. Robert Walpole, Manager, Licensing at (914) 734-6710.
Sincerely, JEP/sp cc:
Mr. Samuel J Collins, Regional Administrator, NRC Region I NRC Resident Inspector's Office, Indian Point 3 Mr. Paul Eddy, New York State Public Service Commission LEREvents@inpo.org
Abstract
On March 2, 2010, at approximately 19:18 hours, an engineering evaluation determined that there were instances of past performance that may have affected the operability of the Reactor Coolant System 31 wide range cold leg temperature loop T-413B required by Technical Specification (TS) 3.3.4, Remote Shutdown.
The review concluded that the remote cabinet electro switch instrumentation switch used to transfer the circuit from the Control Room to the remote shutdown cabinet had evidence of high resistance on the contacts.
This is a resistance measuring circuit and changes in resistance can affect the accuracy of the instrument.
This was evaluated and a conclusion was reached that the plant had been in a condition outside TS and that constituted a safety system functional failure due to repeat surveillance failures.
The cause was transfer switch high resistance.
This was not identified due to poor change management and lack of proper program implementation.
Completed corrective actions were a surveillance to demonstrate the current operability of the instrument successfully performed on March 2, 2010 when past inoperability was identified, revised the calibration procedure to provide adequate steps for performing R/I calibrations and proper as found criteria, and the current set point drift review process now provides a more timely review of as found calibration results for potential impacts on set point drift.
Scheduled corrective action is to revise the calibration procedure to ensure CR and remote shutdown indications are consistent.
This condition had no significant effect on public health and safety.
(If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
Corrective Actions
The following corrective actions have been or will be performed under Entergy's Corrective Action Program to address the cause and prevent recurrence:
" Performed a surveillance to demonstrate the current operability of the instrument on March 2, 2010 when past inoperability was identified.
" Procedure 3-PC-OL01B was revised to provide adequate steps for performing R/I calibrations, switch contact resistance checks, and proper as found criteria.
- The current set point drift review process provides a timely review of as found calibration results for potential impacts on set point drift.
- Procedure 3-PC-OL01B will be revised to ensure CR and remote shutdown indications are consistent.
Event Analysis
The event is reportable under 10 CFR 50.73(a)(2)(i)(B).
The licensee shall report any operation or condition which was prohibited by the Technical Specifications (TS).
This event meets the reporting criteria because TS 3.3.4 limits the loss of the remote shutdown function to 30 days before shutdown is required.
The exact period of time the cold leg temperature loop was out of service could not be determined but it would have exceeded that period.
This event is reportable under 10 CFR 50.73(a) (2) (v) (A).
The licensee shall report any event or condition that could have prevented the fulfillment of the safety function of structures or systems to shutdown the reactor.
The cold leg monitor for the remote shutdown function is limited to the 31 loop and there are no redundant instruments.
Past Similar Events A review was performed of the past three years for Licensee Event Reports (LERs) reporting a safety system functional failure.
LER-2009-009 identified the loss of a neutron flux detector but determined the cause was lack of recurring preventative maintenance.
LER-2008-002 identified the loss of 31 pressurizer backup heater transformer but determined the cause was due to insulation breakdown.
Safety Significance
This event had no effect on the health and safety of the public.
There were no actual safety consequences for the event because there was no shutdown using the remote shutdown panel.
There were no significant potential safety consequences of this event because the remote shutdown instrument is not credited for any accident response in the plant accident analysis.