ENS 43021
ENS Event | |
|---|---|
13:58 Dec 3, 2006 | |
| Title | Accident Mitigation - High Pressure Core Spray (Division 3) Emergency Diesel Inoperable |
| Event Description | On December 3, 2006, at 0858 hours0.00993 days <br />0.238 hours <br />0.00142 weeks <br />3.26469e-4 months <br />, control room operators received a Division 3 Emergency Diesel Generator (EDG) Carbon Dioxide (CO2) (Fire Protection) system initiation signal. The CO2 system for the Division 3 EDG room was out of service at the time and so no CO2 was released into the room. At 0905 hours0.0105 days <br />0.251 hours <br />0.0015 weeks <br />3.443525e-4 months <br />, a first responder notified the control room operators that there was no indication of a fire in the Division 3 EDG room. A walkdown of the associated EDG room ventilation system confirmed the ventilation system tripped with the CO2 initiation signal locked in. At 0919 hours0.0106 days <br />0.255 hours <br />0.00152 weeks <br />3.496795e-4 months <br />, the Division 3 EDG was declared inoperable and Technical Specification (TS) LCO 3.8.1 Condition B was entered. The required TS actions were implemented. The Division 3 EDG is available with restoration of the ventilation system using the CO2 Override switch. The CO2 initiation signal is currently locked in, and the Division 3 CO2 Fire Monitoring Panel, with associated equipment has been quarantined for further investigation.
The Division 3 EDG provides emergency AC electrical power to the High Pressure Core Spray system. This event is being reported as a condition that could have prevented the safety function of structures or systems required to mitigate the consequences of an accident. The Resident Inspector has been notified.
The purpose of this call is to retract Event Number 43021. On December 3, 2006, at 1520 hours0.0176 days <br />0.422 hours <br />0.00251 weeks <br />5.7836e-4 months <br />, a notification, Event Number 43021, was made to the NRC Operations Center by the Perry Nuclear Power Plant (PNPP) in accordance with 10 CFR 50.72(b)(3)(v)(D) as a condition that at the time of discovery could have prevented the fulfillment of the safety function of a system that is needed to mitigate the consequences of an accident. A spurious Carbon Dioxide (CO2) Fire Protection system initiation signal resulted in a tripped condition for the Division 3 Emergency Diesel Generator (EDG) room ventilation system. Operators declared the Division 3 EDG inoperable and took the appropriate Technical Specification actions. The Division 3 EDG provides emergency AC electrical power to the High Pressure Core Spray system. The High Pressure Core Spray system is a single train safety system. After further evaluation, it was determined that operators could promptly restore the ventilation system, with the CO2 initiation signal locked in, if the Division 3 EDG was needed, and that the safety function of the system could still be fulfilled during the time in question. Because the condition reported in Event Number 43021 would not have prevented the fulfillment of the safety function of a system that is needed to mitigate the consequences of an accident, the condition is not reportable, and this notification is retracted. The evaluation (i.e., Reportability Review) for this condition is documented in Condition Report 06-10843. The NRC Resident Inspector has been notified. Notified R3DO (Lara). |
| Where | |
|---|---|
Perry  Ohio (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:+1.37 h0.0571 days <br />0.00815 weeks <br />0.00188 months <br />) | |
| Opened: | Jim Case 15:20 Dec 3, 2006 |
| NRC Officer: | Bill Gott |
| Last Updated: | Dec 14, 2006 |
| 43021 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |