ENS 52334
ENS Event | |
|---|---|
07:39 Oct 31, 2016 | |
| Title | |
| Event Description | On October 31, 2016, at 0239 hours0.00277 days <br />0.0664 hours <br />3.95172e-4 weeks <br />9.09395e-5 months <br /> [CDT], a defect (minor audible through-wall leak) was identified on the steam line drain valve 1-2301-55, HPCI Steam Line Drain Line Steam Trap Outlet Valve. The defect was identified by Operations personnel traversing through the HPCI room as part of normal rounds. HPCI was declared inoperable under Tech Specs 3.5.1, Condition G. The Reactor Core Isolation Cooling (RCIC) system was verified operable. HPCI remains available [but not operable]. The leak has been isolated. The 1-2301-55 is a manual valve downstream of the HPCI steam line drain trap. In a standby line-up, this line drains condensation from the HPCI steam supply line to the main condenser. During operation in an accident scenario, this line drains condensation from the HPCI steam supply line to the Torus via a drain pot. 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 NRC Resident Inspector has been notified. Technical Specification 3.5.1, condition G requires that HPCI be Operable within 14 days.
The purpose of this notification is to retract the ENS Report made on October 31, 2016, at 0239 hours0.00277 days <br />0.0664 hours <br />3.95172e-4 weeks <br />9.09395e-5 months <br /> CDT (ENS#52334). Upon further investigation, a pinhole through-wall leak was discovered in the body of the 1-2301-55 valve (HPCI Steam Line Drain Line Steam Trap Outlet Valve). The defect was characterized as a 1/32-inch rounded hole due to a manufacturing defect in the casting located on the downstream side of the valve near the piping connection. A subsequent evaluation performed by Quad Cities Station considering the defect size, location, and characterization, confirmed the Unit 1 High Pressure Coolant Injection (HPCI) system would have performed its safety function when required. Based on this subsequent evaluation, ENS 52334 is being retracted. Note: On November 1, 2016, at 1624 hours0.0188 days <br />0.451 hours <br />0.00269 weeks <br />6.17932e-4 months <br /> CDT, the 1-2301-55 valve (HPCI Steam Line Drain Line Steam Trap Outlet Valve) was successfully repaired and HPCI was returned to Operable status. The NRC Resident Inspector has been notified. Notified R3DO (Stone). |
| 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:+1.8 h0.075 days <br />0.0107 weeks <br />0.00247 months <br />) | |
| Opened: | Dave Bowman 09:27 Oct 31, 2016 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Dec 5, 2016 |
| 52334 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |