05000247/LER-2006-007, Re Plant in a Condition Prohibited by Technical Specifications Due to Operation of Containment Pressure Relief Valves While Surveillance Requirement Not Met
| ML070450228 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 02/05/2007 |
| From: | Dacimo F Entergy Nuclear Indian Point 2 |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-07-018 LER 06-007-00 | |
| Download: ML070450228 (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 |
| 2472006007R00 - NRC Website | |
text
Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 tBuchanan, N.Y. 10511-0249 EntergyTel (914) 734-6700 Fred Dacimo Site Vice President Administration February 5, 2007 Indian Point 2 Docket No. 50-247 NL-07-018 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop O-P1 -17 Washington, D.C. 20555-0001
Subject:
Licensee Event Report 2006-007-00, "Plant in a Condition Prohibited by Technical Specifications due to Operation of Containment Pressure Relief Valves While Surveillance Requirement Not Met"
Dear Sir:
Pursuant to 10 CFR 50.73(a)(1), Entergy Nuclear Operations Inc. (ENO) hereby provides Licensee Event Report (LER) 2006-007-00. The enclosed LER identifies an event where the plant was operated in a condition prohibited by Technical Specifications, which is reportable under 10 CFR 50.73(a)(2)(i)(B). This condition has been recorded in the ENO Corrective Action Program as Condition Report CR-IP2-2006-6322.
There are no new commitments identified in this letter. Should you have any questions regarding this submittal, please contact Mr. Patric W. Conroy, Manager, and Licensing at (914) 734-6668.
Sincerely, Fred R. Dacimo Site Vice President Indian Point Energy Center cc:
Mr. Samuel J Collins, Regional Administrator, NRC Region I NRC Resident Inspector's Office, Indian Point 2 Mr. Paul Eddy, New York State Public Service Commission INPO Record Center
Abstract
On December 5, 2006 at approximately 0923 hours0.0107 days <br />0.256 hours <br />0.00153 weeks <br />3.512015e-4 months <br />, Engineering determined that Containment isolation valves for the Containment pressure relief line had been inoperable but not closed and deactivated or operated under administrative controls contrary to Technical Specification (TS) requirements.
This appears to have occurred several times since at least August 8,
- 2006, when stroke timing anomalies were identified during quarterly stroke testing.
The direct cause of the TS prohibited condition was failure of the containment relief valves to be limited to the TS maximum stroke of 60 degrees open and failure of the containment relief valves to close within the specified Inservice Testing Program stroke time requirement.
The apparent cause is the dislodging of the travel stop retaining clip due to a poor design that can lead to uneven loading of the travel stop plate.
This can occur initially or through wear of the retaining clips and grooves during normal usage.
Corrective action was taken to repair the valves, augment the maintenance procedure (by providing design details and inspection requirements),
and implementation a modification of the travel stop design to provide a more reliable design.
There was no significant safety hazard since the valves were capable of performing their safety function.
(If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
Event Analysis
This event is reportable under 10 CFR 50.73(a) (2) (i) (B),
any event or condition that resulted in the nuclear power plant operating in a condition prohibited by TS.
The Containment pressure relief valves were found in an inoperable condition that is only detected when performing inspections or timing of strokes.
This appears to have occurred several times since at least August 8,
- 2006, when stroke timing anomalies were identified during the quarterly stroke testing per 2-PT-Q13.
The valves were declared inoperable and repaired.
The diagnosis that the identified condition allowed the pressure relief valves to open 60 degrees or more was reached on December 5, 2006.
Since the pressure relief valves may be opened to relieve containment pressure every few days for approximately 2 -4 hours at a time, and the event condition is not always identifiable, the valves have most likely been inoperable during a time that the pressure control valve(s) had power and that pressure has been relieved without proper administrative controls.
This is a condition prohibited by Technical Specifications.
The time that this has occurred is not identifiable to establish the period of non-compliance with the Technical Specifications.
A review was conducted of Licensee Event Reports (LER) in the past two years for non-compliance with TS.
IP2 reported three events resulting in operations prohibited by Technical Specifications.
LER-2005-001 reported inoperable Component Cooling Water check valves that resulted in an inoperable Emergency Core Cooling train.
LER 2005-002 reported an inoperable Safety Injection pump due to gas binding.
LER 2006-002 reported two inoperable Post Accident monitors.
No common cause was identified.
Safety Significance
This event had no significant effect on the health and safety of the public.
There were no actual safety consequences because Containment integrity was not required by an actual event.
Additionally, there was no significant effect on the public health and safety as no loss of safety function for the Containment isolation valves occurred.
The ability of the pressure relief valves to close from a full open position was evaluated and operability calculation IP-CALC-06-00373 demonstrates that the valves were capable of closing on demand.