ENS 44926
ENS Event | |
|---|---|
16:07 Mar 21, 2009 | |
| Title | Hpci Declared Inoperable Following Failure of Valve to Fully Open During Surveillance Test |
| Event Description | The Peach Bottom Atomic Power Station Unit 3 High Pressure Coolant Injection System (HPCI) was declared inoperable at 12:07 on March 21. 2009 when HPCI Outboard Suppression Pool Suction Valve, MO-3-23-057, failed to fully open during testing. At this time the cause of the failure of MO-3-23-057 to stroke fully open is unknown. Investigation is in progress.
This places Unit 3 in two (2) Tech Spec LCO Action Statements; 3.5.1 (14 day restoration with HPCI inop) and 3.6.1.3, Condition A (4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> immediate action with verification every 31 days of Primary Containment Isolation Valves). Actions required by both have been completed. The failure occurred during performance of the quarterly surveillance test. The licensee informed the NRC Resident Inspector.
The purpose of this notification is to retract a previous report made on 3/21/09 at 1815 hours0.021 days <br />0.504 hours <br />0.003 weeks <br />6.906075e-4 months <br /> (EN# 44926). Notification of the event to the NRC was initially made as a result of declaring the Unit 3 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-57) 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-57 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-57 concern, the suction source from the Suppression Pool was isolated in accordance with Technical Specifications since MO-57 is listed 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. |
| 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:+2.13 h0.0888 days <br />0.0127 weeks <br />0.00292 months <br />) | |
| Opened: | Chris Lally 18:15 Mar 21, 2009 |
| NRC Officer: | Steve Sandin |
| Last Updated: | May 6, 2009 |
| 44926 - NRC Website
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Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |