Open House Held re Performance of Prairie Island Nuclear Plant

On May 18, 2016, the U.S. Nuclear Regulatory Commission (NRC) held an open house in Red Wing, Minnesota to discuss the agency’s annual assessment of safety performance for Prairie Island.  Northern States Power Co.-Minnesota operates the two-unit plant.  It is located in Welch, Minnesota—approximately 28 miles southeast of Minneapolis.

The NRC determined that the Prairie Island facility operated safely in 2015.  All performance indicators and inspection findings for Unit 1 were green or low safety significance and the unit remained in Column 1 of the action matrix throughout the year.  Unit 2, which was in Column 1 for the first three quarters of 2015, moved to Column 2 during the last quarter due to one white performance indicator of low to moderate significance in the area of unplanned scrams.  This performance indicator tracks the number of times the plant shut down unexpectedly during a specific period when the plant was operating at full power.

The NRC uses color-coded inspection findings and performance indicators to assess nuclear plant performance.  The colors start with green and then increase to white, yellow, or red, reflecting the safety significance of the issues involved.  Performance indicators are statistical measurements of plant and equipment performance.  The NRC’s action matrix reflects overall plant performance and agency response.  There are five columns in the matrix with Column 1 requiring a baseline level of inspections.  A move to the other columns results in an increased level of NRC oversight and inspections.

The NRC will conduct a supplemental inspection at Unit 2 to determine if the plant had understood the cause of the white performance indicator and taken sufficient corrective actions to prevent recurrence.  Unit 1 will continue to receive the NRC’s normal level of oversight during 2016.

Inspections are performed by two NRC Resident Inspectors assigned to the plant, inspection specialists from the Region III Office, and specialists from the agency’s headquarters in Rockville, Maryland.  Among the areas of performance to be inspected this year by NRC inspectors are radiological safety, spent fuel storage, and the plant’s ability to identify and resolve problems.

For additional information, please contact Viktoria Mitlyng at (630) 829-9662 or Prema Chandrathil at (630) 829-9663.