NRC CAL – NOV (White)

On January 27, 2009, a Notice of Violation was issued to Northern States Power Company for a violation of Technical Specifications associated with a White Significance Determination finding at Prairie Island Nuclear Generating Plant. Specifically, the licensee failed to adequately control the position of a normally open pressure switch block valve for the Unit 1 turbine-driven auxiliary feedwater pump. The valve was inadvertently left closed, causing the turbine-driven auxiliary feedwater pump to fail to operate as required following a July 31, 2008, Unit 1 reactor trip. The pump was subsequently determined to have been inoperable for 138 days, a time period that significantly exceeded that allowed by the Technical Specifications.