ENS 48712
ENS Event | |
|---|---|
17:45 Feb 3, 2013 | |
| Title | Informational Notification - Safety Relief Valve Potentially Inoperable |
| Event Description | On February 3, 2013 at 1245 EST, with the reactor at 100% core thermal power (CTP) safety relief valve, RV-203-3B was declared inoperable as required by station procedural direction due to an observed reduction in first stage pilot valve temperature of greater than 35 degrees F from baseline temperatures. At 1300 EST, reactor power was lowered to approximately 80% CTP at which time the relief valve parameters returned or trended to normal steady state values. Consistent with a reactor power reduction, reactor pressure also lowered from 1035 psig to 1000 psig. This action was taken consistent with industry operating experience related to three stage target rock relief first stage pilot valve leakage.
Currently, station engineering is evaluating the operability of RV-203-3B. Additionally, the current valve performance is being closely monitored by the main control room operating crew. Station Technical Specification 3.6.D.1 requires that the safety modes of all relief valves (four for [Pilgrim Nuclear Power Station] PNPS) shall be operable during reactor power operating conditions and prior to reactor startup from a Cold Shutdown, or whenever reactor coolant pressure is greater that 104 psig and temperature is greater than 340 degrees F. If this specification is not met, Technical Specification 3.6.D.2 requires that an orderly shutdown shall be initiated and the reactor coolant pressure shall be below 104 psig within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. This is an informational notification at this time. PNPS has not initiated an orderly shutdown as of this notification; rather reactor power was lowered to reseat the safety relief pilot valve and there is a high degree of confidence that the high standard of operability will be restored for RV-203-3B and the associated Technical Specification will be exited. If RV-203-3B is not restored to an operable status, a formal and required notification will be completed in accordance with 10 CFR 50.72(b)(2)(i), 'Initiation of any plant shutdown required by the Technical Specifications.' This event has no impact on the health and safety of the public. The USNRC Senior Resident Inspector has been informed [by the Licensee]. |
| Where | |
|---|---|
| Pilgrim Massachusetts (NRC Region 1) | |
| Reporting | |
| Information Only | |
| Time - Person (Reporting Time:+1.92 h0.08 days <br />0.0114 weeks <br />0.00263 months <br />) | |
| Opened: | Joe Bracken 19:40 Feb 3, 2013 |
| NRC Officer: | John Shoemaker |
| Last Updated: | Feb 3, 2013 |
| 48712 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (80 %) |
Pilgrim with Information Only | |
WEEKMONTHYEARENS 511742015-05-13T04:00:00013 May 2015 04:00:00
[Table view]Information Only Voluntary Report - Information Only ENS 487122013-02-03T17:45:0003 February 2013 17:45:00 Information Only Informational Notification - Safety Relief Valve Potentially Inoperable 2015-05-13T04:00:00 | |