ENS 41676
ENS Event | |
|---|---|
01:36 May 7, 2005 | |
| Title | Degraded Pipe Restraint on Hpci Discharge Piping |
| Event Description | This non-emergency 8-hour report is pursuant, to 10CFR50.72(b)(3). On 05/06/05 at 21:36, [High Pressure Coolant Injection] HPCI was declared inoperable based on a degraded pipe restraint and a degraded snubber associated with the Unit 3 HPCI discharge piping. The degraded pipe restraint and snubber were discovered on 05/05/05 at 17:05.
The subsequent engineering evaluation determined that HPCI is inoperable until the supports are repaired. Reactor operation is unaffected and Unit 3 remains at 100% power. The inoperability of the HPCI system places the plant in a 14 day Limiting Condition of Operation, per [Technical Specification] TS 3.5.1. Further investigation of the cause is in progress. The licensee notified the NRC Resident Inspector.
The purpose of this notification is to retract a previous report made on 5/7/05 at 0016 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> (EN# 41676). Notification of this issue to the NRC was initially made as a result of declaring the Unit 3 High Pressure Coolant Injection (HPCI) system inoperable on 5/6/05 at 2136 hours0.0247 days <br />0.593 hours <br />0.00353 weeks <br />8.12748e-4 months <br />. This declaration was based on a preliminary Engineering evaluation concerning degraded pipe supports associated with the Unit 3 HPCI discharge piping. Since the initial report, it was determined that two HPCI discharge pipe supports required additional Engineering analysis to assess the as-found condition of the pipe supports. One support (S300) had loose base plate bolts while the other support (S46) had cracked welds. Engineering has determined that the S46 HPCI pipe support in the as-found condition was capable of performing its design function. A piping stress analysis was performed to address the as-found condition of the S300 pipe support. This analysis determined that the HPCI system would remain operable with the S300 support out of service. Therefore, during the period of pipe support degradation, the HPCI system was considered as available and capable of performing its safety function. Maintenance was planned and repairs were performed to HPCI system pipe supports. These repairs were complete and the HPCI system was restored to full compliance on 5/9/05 by approximately 0430 hours0.00498 days <br />0.119 hours <br />7.109788e-4 weeks <br />1.63615e-4 months <br />. A root cause evaluation is being performed in accordance with the Corrective Action Program (CR 332355). The NRC resident has been informed of the retraction. Notified R1DO (Krohn). |
| 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:+-1.33 h-0.0554 days <br />-0.00792 weeks <br />-0.00182 months <br />) | |
| Opened: | Robert Steigerwald 00:16 May 7, 2005 |
| NRC Officer: | John Knoke |
| Last Updated: | Jun 14, 2005 |
| 41676 - NRC Website | |
Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |