ENS 49169
ENS Event | |
|---|---|
07:00 Jul 3, 2013 | |
| Title | Notice of Unusual Event Due to Explosion in a Non-Safety Related Load Center |
| Event Description | The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73.
On 7/2/2013, at approximately 2027 MST, Palo Verde Unit 1 experienced a reactor power cutback from 100% rated thermal power due to explosion [in a non-safety related load center (1ENGNL02)]. The unit was at normal temperature and pressure prior to the cutback. At 2035 [MST] PVNGS Unit 1 declared an Unusual Event due to the explosion EAL HU 2.2. Unit 1 is stable at 61% rated thermal power. No ESF actuations occurred and none were required. The event did not result in any challenges to the fission product barrier or result in any releases of radioactive materials. There were no adverse safety consequences or implications as a result of this event. The event did not adversely affect the safe operation of the plant or health and safety of the public. The licensee will notify the NRC Resident Inspector. Notified DHS SWO, FEMA, DHS NICC, and Nuclear SSA via email.
Palo Verde Unit 1 is stable at 58% rated thermal power and is implementing abnormal operating procedures for reactor power cutback due to loss of one Main Feedwater Pump and degraded electrical power due to loss of non-class 13.8kV load center 1ENGNL02. Load center 1ENGNL02 was damaged from an apparent electrical malfunction that originated within the load center. The 13.8kV supply breaker to load center 1ENGNL02 tripped to deenergize the load center. Palo Verde Fire Department personnel responded but determined that the load center was deenergized and no fire existed and no extinguishing agents were applied. No damage to other equipment in proximity to load center 1ENGNL02 was identified during a preliminary inspection of the area around the damaged load center. The NRC Resident Inspector has been notified. At 2315 [MST] on 07/02/2013, the Unusual Event was terminated. Notified R4DO (Gaddy), NRR EO (Nieh), IRD MOC (Gott), DHS SWO, FEMA, DHS NICC, and Nuclear SSA via email. |
| Where | |
|---|---|
Palo Verde  Arizona (NRC Region 4) | |
| Reporting | |
| Emergency class: | Unusual Event |
| 10 CFR 50.72(a) (1) (i), Emergency Class Declaration | |
| Time - Person (Reporting Time:+-6.6 h-0.275 days <br />-0.0393 weeks <br />-0.00904 months <br />) | |
| Opened: | James Blazek 00:24 Jul 3, 2013 |
| NRC Officer: | Pete Snyder |
| Last Updated: | Jul 3, 2013 |
| 49169 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (61 %) |
WEEKMONTHYEARENS 524352016-12-15T11:10:00015 December 2016 11:10:00
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