United States Nuclear Regulatory Commission - Protecting People and the Environment

Special NRC Oversight at Fort Calhoun Station

As a result of the continuous performance assessment of Fort Calhoun Station (FCS), the U.S. Nuclear Regulatory Commission (NRC) modified its regulatory oversight of FCS, effective December 13, 2011, to address several performance issues that were identified during an extended shutdown of the plant. FCS initially shut down for a scheduled refueling outage in April 2011, but that outage was subsequently extended to address longstanding technical issues, as well as issues associated with the Missouri River flooding that affected the plant from June through September 2011. Because the identified performance issues will require additional oversight, the NRC will now follow Inspection Manual Chapter 0350 (IMC 0350), “Oversight of Reactor Facilities in a Shutdown Condition Due to Significant Performance and/or Operational Concerns,” rather than the usual IMC 0305, “Operating Reactor Assessment Program.”

The following table lists the publicly available documents that the NRC has issued in connection with the special oversight of FCS.

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Date Title/Description
10/02/2012 NRC Resident Inspection Report
08/23/2012

Public Meeting Notice

08/13/2012 NRC Resident Inspection Report
07/17/2012

Summary of Public Meeting with Omaha Public Power District

07/09/2012 Fort Calhoun Station Integrated Performance Improvement Plan
06/29/2012 Public Meeting Notice
06/13/2012 Triennial Fire Protection Inspection Report
06/13/2012 Designation of NRC Oversight Panel Chairman
06/11/2012 Fort Calhoun Station Response to NRC Inspection Report 2012002
06/11/2012 Confirmatory Action Letter and Restart Checklist
05/02/2012 Public Meeting Notice
04/04/2012

Summary of Public Meeting with Omaha Public Power District

02/22/2012

Transcript of Public Meeting Held at NRC, Briefing on Fort Calhoun Station

02/12/2012 Manual Chapter 0350 Panel Process Plan for Fort Calhoun Station 
01/19/2012

Summary of Public Meeting with Omaha Public Power District

01/12/2012 Fort Calhoun Station Manual Chapter 0350 Oversight Panel Charter
12/13/2011 Notification of Change to Regulatory Oversight of Fort Calhoun Station
09/02/2011 Confirmatory Action Letter

Electrical Switchgear Fire Event

  • A fire occurred on June 7, 2011, in electrical switchgear that distributes power to vital systems and components needed for the safe shutdown of the plant. This fire affected two independent trains of the system and resulted in the NRC issuing a preliminary red finding on March 12, 2012, following a special inspection. The special inspection report is found in the below documents.

  • The fire started in a replacement electrical breaker that was modified to fit inside the existing electrical switchgear. The replacement breaker was installed and in service for about 18 months before the fire occurred.

  • Poor alignment between electrical components and inadequate cleaning of the connections (hardened grease at the interface) increased the electrical resistance at their junction.  These conditions created a buildup of heat that caused a fire affecting one train; electrically conductive soot and smoke spread past a barrier and tripped the breaker on the opposing train. This electrical fault resulted in the complete loss of spent fuel pool cooling for approximately 90 minutes, resulting in a 3°F temperature rise in the pool.

  • Fort Calhoun Station staff has taken compensatory measures to ensure that high resistance connections were corrected in the other affected load centers, and reactor shutdown cooling systems were not directly affected. The NRC is in the process of reviewing Fort Calhoun Station’s actions in response to the fire. The reactor at Fort Calhoun Station is currently shutdown and will not be allowed to restart until the IMC 0350 Panel grants approval.
Date Description
05/24/2012 OPPD Reply to Red Finding
04/10/2012 Final Significance of Red Finding
03/12/2012 Special Inspection Report
10/27/2011 Licensee Event Report
09/12/2011 NRC Press Release
06/08/2011 ALERT Exited
06/07/2011 ALERT Declared
Page Last Reviewed/Updated Monday, October 15, 2012