FirstEnergy Nuclear Operating Company (FENOC) plans to accelerate the replacement of the reactor head at its Davis-Besse Nuclear Power Station in Oak Harbor, Ohio, by three years. The 908MW unit is now scheduled to shut down in the autumn of 2011 for the installation, instead of 2014.
Davis-Besse is currently preparing for restart (expected by July) following a scheduled refueling outage where 24 of 69 control rod nozzles were modified to ensure their structural integrity. Installing the new head with nozzles made of material less susceptible to primary water stress corrosion cracking will further enhance safe and reliable operations at the unit.
"We are confident that the process used to modify the affected nozzles was successful," said James Lash, FENOC president and chief nuclear officer. "Post-modification inspections and tests indicate these nozzles will support continued safe and reliable operations. At the same time, advancing the installation of the new reactor head will provide additional margins of safety and reliability for long-term plant operations."
The new reactor head has been manufactured by Areva and is currently stored in France. The head is expected to arrive at Davis-Besse in autumn of 2010 where it will undergo a series of pre-service inspections. Plans to install the head are now under development.
On 5 March 2002, maintenance workers discovered that corrosion had eaten a football-sized hole into the reactor vessel head of the Davis-Besse nuclear power plant. Although the corrosion did not lead to an accident, this was considered to be a serious nuclear safety incident.
The Nuclear Regulatory Commission kept Davis-Besse shut down until March 2004, when the agency was convinced the plant operator, FENOC, had performed all the necessary maintenance for safe operations. The company also agreed to an order that required several actions to reform its operations approach and ensure safety was the top priority. In September 2009, the NRC ruled that FENOC had met the terms of the order.
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