ENS 42622
ENS Event | |
|---|---|
20:00 Jun 6, 2006 | |
| Title | Failure to Meet Emergency Equipment Service Water Surveillance Requirement |
| Event Description | On June 6, 2006 at 1600 EDT the Division 2 Emergency Equipment Service Water System (EESW) was in service for a planned surveillance test when the system failed to achieve required flows as specified in the surveillance. These flow rates are acceptance criteria and therefore resulted in system inoperability. EESW cools the Emergency Equipment Cooling Water (EECW) System which in turn cools various safety related components including the High Pressure Coolant Injection (HPCI) System Area Cooler. Unplanned HPCI inoperability occurred due to the Division 2 EECW/EESW inoperability based on loss of the HPCI System Area Cooler. A 14 day Limiting Condition for Operation (LCO) was entered for HPCI per LCO 3.5.1. This report is being made pursuant to 10CFR50.72(b)(3)(v)(D) as a condition that at the time of discovery could have prevented the fulfillment of a safety function needed to mitigate the consequences of an accident, based on loss of a single train safety system."
The licensee notified the NRC Resident Inspector.
On June 6, 2006 at 1600 EDT, during the performance of the quarterly pump and valve operability surveillance test on Division 2 of the Emergency Equipment Service Water System (EESW), the minimum pump flow required by the procedure to perform the test could not be established. Because minimum pump flow could not be established, Division 2 of EESW was declared inoperable. EESW cools the Emergency Equipment Cooling Water (EECW) System which in turn cools various safety related components including the High Pressure Coolant Injection (HPCI) System Area Cooler. HPCI was declared inoperable based on loss of the HPCI System Area Cooler due to the Division 2 EECW/EESW inoperability. A 14 day Limiting Condition for Operation (LCO) was entered for HPCI per LCO 3.5.1. A report was made to the NRC pursuant to 10CFR50.72(b)(3)(v)(D) as a condition that at the time of discovery could have prevented the fulfillment of a safety function needed to mitigate the consequences of an accident, based on loss of a single train safety system. On June 7, 2006, the test was re-performed with the valve in the bypass line around the heat exchanger Temperature Control Valve (TCV) throttled open. The required pump flow was established and the surveillance was successfully completed at 1815 EDT. Further Engineering evaluation concluded that minimum pump flow could not be established on June 6, 2006 due to normal pump wear and heat exchanger fouling. The pump flow required for performing the pump and valve operability surveillance test was established to monitor pump degradation and is higher than the flow required for the EESW system to perform its safety function. It has been verified that the measured flow exceeds the system design basis required flow with an adequate margin and that the pump and heat exchanger remain adequate to support the HPCI room cooling operation. The HPCI safety function was maintained throughout this period; therefore, this event is being retracted. The licensee notified the NRC Resident Inspector. Notified the R3DO (Louden). |
| Where | |
|---|---|
Fermi  Michigan (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:+3.15 h0.131 days <br />0.0187 weeks <br />0.00431 months <br />) | |
| Opened: | Mike Himebauch 23:09 Jun 6, 2006 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Jun 15, 2006 |
| 42622 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |