ENS 50237
ENS Event | |
|---|---|
05:06 Jun 29, 2014 | |
| Title | Unusual Event - Earthquake Felt on Site |
| 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.
An event classification of Unusual Event (HU1.1) was declared at 22:17 MST for the Palo Verde Nuclear Generating Station because of an earthquake that originated 50km NW of Lordsburg, New Mexico at 21:59 MST. Per the USGS website, the magnitude of the earthquake was 5.2 on the Richter scale. Initial walkdowns of plant equipment and review of plant parameters have found no unusual conditions or damage to plant equipment. No abnormalities caused by the seismic event were observed. No reactor protection system (RPS) or engineered safety feature (ESF) actuations occurred and none were required. Palo Verde Unit 1, 2, and 3 are at 100 percent power with all offsite power supplies available. Initial analysis of the Seismic Monitoring Instrumentation System indicated a seismic event, below the magnitude of the 0.10g spectra Operating Basis Earthquake (OBE) and the 0.20g spectra Safe Shutdown Earthquake (SSE). The NRC Resident Inspector has been notified of seismic activity and this ENS call. This event time is 2206 MST because this is the time the control room was notified by plant Operators that an earthquake had been felt on site. Notified DHS, FEMA, and NICC. FEMA NWC and Nuclear SSA were notified via email.
Emergency classification termination was declared at 6/29/14 01:12 MST. All required power block inspections were completed with no deficiencies noted. No other conditions require an emergency classification, there are no challenges to fission product barriers or radiological release, and plant conditions offer no possibility of adverse impact on health and safety of the public. The licensee notified the NRC Resident Inspector, state and local governments. Notified the R4DO (Allen), NRR (Hiland), IRD (Gott), DHS, FEMA, and NICC. FEMA NWC and Nuclear SSA were notified 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:+-3.2 h-0.133 days <br />-0.019 weeks <br />-0.00438 months <br />) | |
| Opened: | Dennis Martin 01:54 Jun 29, 2014 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Jun 29, 2014 |
| 50237 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 576592025-04-10T14:11:00010 April 2025 14:11:00
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