ENS 44593
ENS Event | |
|---|---|
16:17 Oct 22, 2008 | |
| Title | Rcic Declared Inoperable Due To Aging Concern Of Several Flow Controller Components |
| Event Description | On October 22, 2008, at 1217 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.630685e-4 months <br />, with the reactor at 100% core thermal power and steady state conditions, Pilgrim Nuclear Power Station (PNPS) conservatively declared the Reactor Core Isolation Cooling System (RCIC) inoperable in response to a concern regarding the reliability of aged capacitors that are installed in the RCIC flow controller.
As background, the RCIC flow controller was calibrated and successfully tested on October 7th, 2008 as part of normal surveillance activities, however several of the capacitors installed in the controller were noted to be between 21 to 30 years of age. Industry recommended replacement interval for the capacitors is typically between 7 to 10 years of age. PNPS engineering review in conjunction with Entergy fleet consultation concluded today (10/22) that there was no definitive technical bases to provide a reasonable expectation that the RCIC flow controller function can be assured throughout it's mission time due to the capacitor aging concern. Therefore, RCIC was declared inoperable and a 14 day limiting condition for operability action statement was entered in accordance with TS 3.5.D.1. A replacement controller is being prepared for installation, with post maintenance testing projected to be completed by 2100 hours0.0243 days <br />0.583 hours <br />0.00347 weeks <br />7.9905e-4 months <br /> this evening. Ultimately the suspect controller will be the subject of further evaluation and this notification will be updated as appropriate. This notification has no impact on the health and safety of the public. The NRC Senior Resident Inspector is onsite and has been notified. This is an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> notification made in accordance with 50.72(b)(3)(v)(D).
Basis for Retraction: Event Notification 44593 was conservatively made to ensure that the eight-hour non-emergency reporting requirements of 10 CFR 50.72 were satisfied pending the evaluation of RCIC System operability. On 10/22/08, RCIC flow controller FIC-1340-1 was declared inoperable due to engineering uncertainty for controller operability. The controller's electrolytic capacitors appeared to be aged beyond the expected useful life, and the resultant degrading power supply voltage indicated that the controller may not operate for the required FSAR mission time of eight hours. The controller was replaced on 10/23/08 with a refurbished controller and subsequent post-maintenance RCIC system flow testing demonstrated RCIC system operability. The controller that was removed from service was evaluated. Controller bench testing was performed on 11/6 and 11/7, 2008. This testing demonstrated that the controller could provide a full demand output signal for a minimum of 15 continuous hours. During this testing, it was also determined that the power supply output voltage was not degrading. Based on this post-service controller testing, and the successful in-service RCIC flow controller calibration and system performance test conducted on 10/07/08, the controller was operable when installed. The RCIC system was capable of performing its intended safety functions and would have started and supplied design basis flow to the reactor vessel under design basis conditions. Thus there would have [been] no impact on nuclear safety. Therefore, this event was not reportable pursuant to 10CFR50.72(b)(3)(v)(D). Event Number 44593, made on 10/22/2008, is being retracted. The licensee notified the NRC Resident Inspector. Notified R1DO (Bellamy). |
| Where | |
|---|---|
| Pilgrim Massachusetts (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+1.42 h0.0592 days <br />0.00845 weeks <br />0.00195 months <br />) | |
| Opened: | Mert Probasco 17:42 Oct 22, 2008 |
| NRC Officer: | Jeff Rotton |
| Last Updated: | Dec 12, 2008 |
| 44593 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |