ENS 44904
ENS Event | |
|---|---|
20:20 Mar 12, 2009 | |
| Title | Hpci Declared Inoperable |
| Event Description | This non-emergency 8-hour report is pursuant to 10CFR50.72(b)(3). On 03/12/09 at 1620, Operations performed [Standard Operating Procedure] S.O. 23.7.B-2 to swap the CST and Torus suctions in conjunction with scheduled I&C testing. While opening the HPCI Torus Inboard Suction valve MO-2-23-58, its travel stopped at approximately the 50% full open position. The HPCI system was declared inoperable per Technical Specification (T.S.) 3.5.1. The HPCI system remains available and the HPCI Torus Outboard Suction valve MO-2-23-57, was closed and de-energized for PCIV isolation as required by T.S. 3.6.1.3.
Both MO-2-23-058 and the Unit 2 HPCl system are inoperable. The valve has been quarantined in accordance with station procedures and required Technical Specification actions have been taken. Reactor operation is unaffected and Unit 2 remains at 100% power. The inoperability of the HPCI system places the plant in a 14 day shutdown Tech Spec action statement. Further investigation of the cause of the valve failure is currently in progress. RCIC has been verified operable. The licensee notified the NRC Resident Inspector.
The purpose of this notification is to retract a previous report made on 3/12/09 at 2324 hours0.0269 days <br />0.646 hours <br />0.00384 weeks <br />8.84282e-4 months <br /> (EN# 44904). Notification of the event to the NRC was initially made as a result of declaring the Unit 2 High Pressure Coolant Injection (HPCI) system inoperable when unexpected conditions were found during performance of routine surveillance testing of HPCI. Specifically, it was noted that a motor-operated Suppression Pool suction valve for HPCI (MO-58) did not complete its stroke in the open direction during testing. The HPCI system was not operating at the time of the discovery. Since the initial report, Engineering has determined that HPCI was capable of performing its safety function. The evaluation determined that the MO-58 valve was capable of opening to a position sufficient to ensure that the HPCI safety function was met for design basis conditions. Additionally, since the torque switch is bypassed during actual design events, full motor torque would have been available which was sufficient to allow the valve to reach its full open position. It has also been determined that the valve was capable of closing on a signal to close automatically. During resolution of the HPCI MO-58 concern, the suction source from the Suppression Pool was isolated in accordance with Technical Specifications since MO-58 is considered as a Primary Containment Isolation Valve. This action was performed in accordance with station procedures and is considered planned maintenance. The NRC resident has been informed of the retraction. Notified R1DO (Caruso). |
| Where | |
|---|---|
Peach Bottom  Pennsylvania (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:+3.07 h0.128 days <br />0.0183 weeks <br />0.00421 months <br />) | |
| Opened: | Brad Kirkmon 23:24 Mar 12, 2009 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | May 6, 2009 |
| 44904 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |