ENS Event | |
|---|---|
09:01 Jun 5, 2011 | |
| Title | Discovery of After-The-Fact Emergency Condition - Unusual Event |
| Event Description | At 1650 [EDT] on 7/20/2011 it was determined that a Notification of Unusual Event (NOUE) was not declared for an event on 6/5/2011. The event occurred at 0501 [EDT] on 6/5/2011 when a low oxygen atmosphere condition was measured in the Unit 2 reactor containment building. The NOUE should have been declared in accordance with Surry Power Station Emergency Action Level HU3.1 (Report or detection of toxic, corrosive, asphyxiant, or flammable gases that have or could enter the Owner Controlled Area in amounts that can affect normal plant operations). This condition occurred during a refueling outage with maintenance being performed using a liquid nitrogen supplied freeze seal. The freeze seal activity released nitrogen, which slowly caused the low oxygen atmosphere (<19.5%).
In accordance with guidance provided in NUREG-1022, a one hour ENS notification is being made due to discovery of an undeclared condition that exceeded an Emergency Action Level. The licensee will inform Surry County, the State of Virginia and has informed the NRC Resident Inspector. |
| Where | |
|---|---|
Surry  Virginia (NRC Region 2) | |
| Reporting | |
| Other Unspec Reqmnt | |
| Time - Person (Reporting Time:+1087.82 h45.326 days <br />6.475 weeks <br />1.49 months <br />) | |
| Opened: | Scott G. Bray 16:50 Jul 20, 2011 |
| NRC Officer: | Steve Sandin |
| Last Updated: | Jul 20, 2011 |
| 47077 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 482392012-08-27T13:00:00027 August 2012 13:00:00
[Table view]Other Unspec Reqmnt Discovery of After-The-Fact Emergency Condition - Alert - High Co2 Concentration in a Safe Shutdown Area ENS 470772011-06-05T09:01:0005 June 2011 09:01:00 Other Unspec Reqmnt Discovery of After-The-Fact Emergency Condition - Unusual Event ENS 466982011-03-25T04:00:00025 March 2011 04:00:00 Other Unspec Reqmnt Non-Compliance with Nuhoms Technical Specification ENS 428902006-10-07T21:11:0007 October 2006 21:11:00 Other Unspec Reqmnt Discovery of After-The-Fact-Emergency Condition - Unusual Event 2012-08-27T13:00:00 | |