ENS 49801
ENS Event | |
|---|---|
17:54 Feb 6, 2014 | |
| Title | Emergency Equipment Cooling Water in Manual Override Due to Human Performance Error |
| Event Description | At 1254 [EST] on February 6, 2014, while shutting down Division 2 Emergency Equipment Cooling Water (EECW), a human performance error occurred resulting in the Division 2 EECW isolation override switch being placed in manual override. Division 2 EECW remained running and continued to operate normally. The Division 2 EECW system cools various safety related components including the High Pressure Coolant Injection (HPCI) system room cooler. With the Division 2 EECW isolation override switch in manual override, Division 2 EECW may have been prevented from performing its safety function during a loss of power event. An unplanned HPCI inoperability occurred due to the Division 2 EECW inoperability which may have prevented HPCI from performing its safety function. A 14 day Limiting Condition for Operation (LCO) was entered for HPCI via T.S. LCO 3.5.1 and subsequently exited 36 seconds later upon returning the Division 2 EECW isolation override switch to normal. 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 a loss of a single train safety system. The NRC Resident Inspector has been notified.
The licensee reported that the individuals involved have been removed from licensee duties pending further investigation.
The Fermi 2 Engineering staff has completed a comprehensive evaluation of the momentary mispositioning of the Division 2 EECW system overide switch initially reported on February 6, 2014. The evaluation determined that HPCI room temperature would remain below the HPCI room steam leak detection isolation logic setpoint in the unlikely event that the momentary mispositioning resulted in the temporary interruption of the cooling water flow to the HPCI system room cooler. Over the brief period of time for which EECW would have been unavailable to support the effective operation of the room cooler, its function was not necessary for HPCI to perform its required safety functions. Therefore, event notification 49801 is retracted. The licensee notified the NRC Resident Inspector. Notified R3DO (Passehl). |
| 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:+1.38 h0.0575 days <br />0.00821 weeks <br />0.00189 months <br />) | |
| Opened: | Paul Gresh 19:17 Feb 6, 2014 |
| NRC Officer: | John Shoemaker |
| Last Updated: | Apr 4, 2014 |
| 49801 - NRC Website | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (85 %) |
| After | Power Operation (85 %) |