ENS 49407
ENS Event | |
|---|---|
01:45 Oct 4, 2013 | |
| Title | Unit 2 High Pressure Coolant Injection (Hpci) Inoperable Due to Drain Line Leak |
| Event Description | On October 3, 2013, at 2045 [CDT] hours, a defect (pinhole through-wall leak) was identified on the drain line for the LS 2-2365, HPCI TURBINE INLET DRAIN POT LEVEL SWITCH. The defect was identified during investigation of leakage near LS 2-2365. The LS 2-2365, HPCI TURBINE INLET DRAIN POT LEVEL SWITCH, is provided to detect a failure of the HPCI steam trap during standby line-up. The location of the defect, is in Class 2 Safety related piping. HPCI is a single train safety system and this notification is being made in accordance with 10CFR50.72(b)(3)(v)(D). The instrument isolations for LS 2-2365 have been close and the leak has been isolated.
There is no increase to plant risk and RCIC (Reactor Core Isolation Cooling) is available. The licensee will inform the NRC Resident Inspector.
The purpose of this notification is to retract the ENS report made on October 4, 2013, at 0212 EDT (ENS 49407). Upon further investigation the pinhole through-wall leak discovered in the Unit 2 HPCI room was in a weld at a 'Tee' downstream of the Unit 2 HPCI turbine inlet drain pot level switch (LS 2-2365) on drain line 2-2386B-1-B. The defect was characterized as a 1/16-inch rounded hole due to gas porosity (with no evidence of cracking). A subsequent evaluation performed by Quad Cities Station considering the defect size, location, and characterization confirmed the Unit 2 High Pressure Coolant Injection (HPCI) system would have performed its safety function when required. Based on this subsequent evaluation, ENS 49407 is being retracted. Note: On October 3, 2013, at 1155 CDT the Unit 2 HPCI drain line leak was isolated and HPCI was declared operable. The licensee has notified the NRC Resident Inspector. Notified R3DO (Lipa). |
| Where | |
|---|---|
Quad Cities  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+0.45 h0.0188 days <br />0.00268 weeks <br />6.1641e-4 months <br />) | |
| Opened: | Mark Bridges 02:12 Oct 4, 2013 |
| NRC Officer: | Pete Snyder |
| Last Updated: | Nov 7, 2013 |
| 49407 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |