ENS 53253
ENS Event | |
|---|---|
13:09 Mar 10, 2018 | |
| Title | High Pressure Coolant Injection System Declared Inoperable |
| Event Description | HPCI [High Pressure Coolant Injection] was removed from service (unplanned) on 3/10/2018 at time 0709 [CST] by closing HPCI-MO-15, STEAM SUPPLY INBOARD ISOLATION. The inboard steam supply isolation valve is inside Primary Containment. The steam supply valve was closed in an effort to isolate [unidentified] leakage to Primary Containment from a suspected packing leak from HPCI-MO-15. After closing the HPCI-MO-15, Reactor Coolant System Leakage parameters returned to within Technical Specification [TS] LCO [Limiting Condition of Operations] 3.4.4 limits.
Entered into Technical Specification LCO 3.5.1 Condition C - HPCI System Inoperable. Required Actions for Condition 'C' are to verify by administrative means RCIC [Reactor Core Isolation Cooling] System is operable within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and restore HPCI System to operable status within 14 days. RCIC was verified operable by administrative means concurrent with declaration of HPCI inoperable. Normal plant shutdown activities are being planned [for 03/11/2018 at 1200 CDT] to support entry into Primary Containment to initiate any necessary repairs. HPCI is a single train safety system. This report is submitted as a condition that at time of discovery could prevent the fulfillment of the safety function of an SSC [System, Structure, or Component] needed to mitigate the consequences of an accident. This condition has been entered into the CNS [Cooper Nuclear Station] Corrective Action Program. CR-CNS-2018-01346 LCO 3.4.4 was entered during unplanned maintenance of the HPCI system. When the HPCI-MO-15 was cycled from closed to open, unidentified leakage in the containment increased above 2 gallons per minute (gpm) in less than a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period. Also, total unidentified leakage exceeded 5 gpm. The licensee closed the HPCI-MO-15 valve resulting in a decrease in unidentified leakage below TS shutdown limit. The NRC Resident Inspector was notified. |
| Where | |
|---|---|
Cooper  Nebraska (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+0.75 h0.0313 days <br />0.00446 weeks <br />0.00103 months <br />) | |
| Opened: | Ryan Lynn 13:54 Mar 10, 2018 |
| NRC Officer: | Ossy Font |
| Last Updated: | Mar 10, 2018 |
| 53253 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |