ENS 46987
ENS Event | |
|---|---|
04:30 Jun 26, 2011 | |
| Title | Piping Leak Isolated on High Pressure Coolant Injection |
| Event Description | On 06/26/11, at 0030 [hrs. EDT], Peach Bottom Atomic Power Station Unit 3 declared the High Pressure Coolant Injection [HPCI] system inoperable for an ASME class 2 exempt piping leak found during operator rounds. Piping on the steam line pressure indication sensing line downstream of a sensing line root valve had an approximate 5 drop per minute leak. The leak has been isolated and the Unit 3 HPCI system was restored to an operable condition as of 0347 on 06/26/11.
This report is being submitted pursuant to 10CFR 50.72(b)(3)(v)(D). The licensee notified the NRC Resident Inspector.
The purpose of this notification is to retract a previous report made on 06/26/11 at 0525 [EDT] (EN# 46987). Notification of this event to the NRC was initially made as a result of declaring the Unit 3 High Pressure Coolant Injection (HPCI) system inoperable on 06/26/11 at 0030 [EDT] when a small leak on an instrument sensing line was found during performance of routine operator rounds. Specifically, it was observed that the 1/2 inch instrument piping for the non-safety related HPCI steam supply pressure indicator was leaking at approximately 5 drops per minute. The location of the leak was downstream of the instrument line root valve. The leak was isolated and the Unit 3 HPCI system was considered operable at approximately 0347 [EDT] on 06/26/11. The ENS report on 06/26/11 was originally submitted to report a potential loss of safety function involving the Unit 3 HPCI system due to this leak. Since the initial report, engineering has determined that HPCI was capable of performing its safety function at the time the instrument sensing line was leaking. The evaluation determined that the small sensing line leak would not have resulted in any significant equipment qualification, internal flooding or other equipment concerns that could have affected the HPCI system capability during any postulated design basis events. The pressure indicating instrument supplied by the sensing line is not safety related and is not required for any HPCI function or HPCI operability. Therefore, HPCI was determined to have maintained its operability during the time period that the HPCI sensing line was leaking. The NRC resident has been informed of the retraction. Notified R1DO (Powell). |
| 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:+0.92 h0.0383 days <br />0.00548 weeks <br />0.00126 months <br />) | |
| Opened: | Roy Glackin 05:25 Jun 26, 2011 |
| NRC Officer: | Pete Snyder |
| Last Updated: | Aug 8, 2011 |
| 46987 - NRC Website
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Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |