ENS 49173
ENS Event | |
|---|---|
07:00 Jul 3, 2013 | |
| Title | Loss of Emergency Response Communications Due to a Loss of Ancillary Power |
| Event Description | At 0156 PDT on July 3, 2013, Diablo Canyon Power Plant experienced a loss of power to ancillary facilities on site. This affected power supplies to data systems used by the Emergency Response Facilities [EOF]. All plant status and performance data in the TSC [Technical Support Center] and EOF is available via telephone bridge line and control room phone talker.
Additionally, the Emergency Response Data System (ERDS) has been determined to be unavailable. The data system loss occurred following depletion of backup batteries in the affected data center." The licensee notified the NRC Resident Inspector and will notify state and local agencies.
At 2120 PDT on 6/23/13, Diablo Canyon Power Plant (DCPP) experienced a loss of the offsite 230 kV startup power source due to an offsite transmission system relay actuation (see EN# 49143). At 1000 PDT on 7/3/13, PG&E identified that the conditions present on 7/3/13 that resulted in loss of plant status and performance data in the Technical Support Center (TSC) and Emergency Operations Facility (EOF) (see EN# 49173) also existed on 6/23/13. This update reports the 6/23/13 loss of plant status and performance data in the TSC and EOF due to loss of power in the data center that supports those facilities. All plant status and performance data required for emergency assessment and communication remained available via a telephone bridge line and control room phone talker. The data became unavailable in the TSC and EOF following depletion of backup batteries in the affected data center. On 7/3/13 PG&E reconfigured the TSC workstations to ensure they would function and provide data for emergency assessment capability independent of the status of the data center power supplies. The Emergency Response Data System was also unavailable following the loss of 230 kV startup power on 6/23/13 due to loss of power to the data center. This unavailability was as designed and as expected. This delayed event notification has been entered into the DCPP corrective action program. The licensee has notified the NRC Resident Inspector. Notified the R4DO (Gaddy) and ERDS Group via email. |
| Where | |
|---|---|
Diablo Canyon  California (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | |
| Time - Person (Reporting Time:+5.85 h0.244 days <br />0.0348 weeks <br />0.00801 months <br />) | |
| Opened: | Dan Stermer 12:51 Jul 3, 2013 |
| NRC Officer: | Vince Klco |
| Last Updated: | Jul 3, 2013 |
| 49173 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (48 %) |
| After | Power Operation (73 %) |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 533612018-04-24T10:57:00024 April 2018 10:57:00
[Table view]10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Containment Radiation Monitors Inoperable ENS 493342013-09-09T20:00:0009 September 2013 20:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Planned Partial Loss of Communications Capability in Technical Support Center ENS 491732013-07-03T07:00:0003 July 2013 07:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Response Communications Due to a Loss of Ancillary Power ENS 487862013-02-27T00:30:00027 February 2013 00:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Assessment Capability Due to Vital Inverter Maintenance ENS 486002012-12-18T02:04:00018 December 2012 02:04:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Plant Vent Continuous Radiation Monitors Inoperable ENS 483392012-09-25T12:55:00025 September 2012 12:55:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Technical Support Center Removed from Service for Maintenance ENS 481712012-08-09T17:00:0009 August 2012 17:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Emergency Operations Facility Data Network Maintenance ENS 443052008-06-19T03:15:00019 June 2008 03:15:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Meteorlogical Mixing Calculations Unavailable ENS 426402006-06-14T16:41:00014 June 2006 16:41:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Erds Inoperable ENS 413022004-12-31T11:15:00031 December 2004 11:15:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Notification Sirens 2018-04-24T10:57:00 | |