No. III-10-016 

Contacts: 

Viktoria Mitlyng 630-829-9662 

Prema Chandrathil 630-829-9663 

 May 17, 2010 

 E-Mail: opa3@nrc.gov 

Web site: www.nrc.gov

NRC TO DISCUSS 2009 PERFORMANCE ASSESSMENT 

FOR PRAIRIE ISLAND NUCLEAR POWER PLANT MAY 20

 The Nuclear Regulatory Commission staff will hold a public meeting with representatives of 

Northern States Power Co. – Minnesota on Thursday, May 20, to discuss the agency’s assessment of 

safety performance for last year at the Prairie Island Nuclear Power Plant. The two-unit plant is 

located in Welch, Minn, roughly 50 miles southeast of Minneapolis. 

 The meeting, which will be open to the public, is scheduled to begin at 6 p.m. CDT at the 

Twin Bluff Middle School Auditorium, 2120 Twin Bluff Rd in Red Wing. The NRC staff will 

present the results of the annual assessment, talk about the NRC and its range of activities and be 

available to respond to questions or comments from the public. 

An NRC “Open House” will be held at 5 p.m. CDT to provide interested members of the 

public with an opportunity to talk informally with agency staff. 

 “The NRC continually reviews the performance of the Prairie Island plant and the nation’s 

other commercial nuclear power facilities,” NRC Region III Administrator Mark Satorius said. 

“This meeting allows us to discuss our annual assessment of safety performance with the company 

and area residents. One of NRC’s main goals is to explain to people in the community how the 

agency regulates nuclear power plants.” 

 A letter sent from the NRC Region III Office to plant officials addresses the performance of 

the plant during the period and will serve as the basis for the meeting discussion. It is available on 

the NRC Web site at: 

http://www.nrc.gov/NRR/OVERSIGHT/ASSESS/LETTERS/prai_2009q4.pdf. 

 Overall, the Prairie Island plant operated safety in 2009. There were, however, some changes 

in inspection findings. 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,” commensurate with the safety significance of the issues involved. 

 A “white” finding of low to moderate safety significance was identified in 2009 for both 

Units 1 and 2. This finding involved a shipment of refueling equipment and tools from the power 

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plant which exceeded regulatory requirements for the transportation of nuclear material established 

by the NRC and Department of Transportation. When the shipment arrived at its destination in Waltz 

Mill, PA, radiation monitors showed that the radiation levels on the underside of the package exceeded the 

allowed radiation levels. The elevated radiation levels were on the underside of the package limiting the 

potential that a member of the public would come into contact with that area of the package. Though the 

finding did not have an actual impact on public health and safety the NRC conducted an additional 

inspection to ensure the utility had taken actions to fully understand and correct the issue.

 An additional “white” finding was indentified for Unit 2 which will result in additional 

oversight. This finding is associated with the inadequate design of the component cooling water 

system which circulates water to cool equipment including the reactor cooling pumps. The reactor 

coolant pumps help circulate water through the reactor during operation. The concern is that certain 

events such as high energy line breaks, severe tornado winds and severe earthquakes could damage 

or break the component cooling water system piping and potentially lose cooling water to the 

equipment. No actual event has occurred. The NRC will conduct a supplemental inspection to make 

sure the problems surrounding the finding have been fully understood and resolved by the utility. 

 The letter also addressed one substantive cross-cutting issue in the area of human 

performance. Cross-cutting issues are issues that “cut across” multiple areas of plant operation. 

Examples of cross-cutting issues include problems associated with the plant staff’s ability to 

develop effective procedures and adhere to these procedures. Cross-cutting issues cannot be 

quantified and are not assigned safety significance. When a substantive cross-cutting issue is 

identified at a nuclear power plant, the NRC expects the problem to be corrected. 

 At Prairie Island, the NRC identified a cross-cutting issue that involved conservative 

assumptions, procedural adequacy and procedural compliance in mid 2009. The NRC held a public 

meeting where the utility discussed their actions to address the problem. Some improvement has 

been seen but these actions have not yet proven effective. These issues will remain open until the 

utility’s actions have resulted in sustainable improvement. 

 Prairie Island will continue to receive the detailed inspection regime used by the NRC for 

plants. Routine inspections are performed by two NRC Resident Inspectors assigned to the plant and 

by inspection specialists from the Region III Office in Lisle, Ill., and the agency’s headquarters in 

Rockville, Md. In addition to the supplemental inspection, the areas of plant operation being 

inspected this year are radiation protection, equipment design and review of the groundwater 

protection initiative. 

 Current performance information for Prairie Island is available on the NRC’s web site at: 

http://www.nrc.gov/NRR/OVERSIGHT/ASSESS/PRAI1/prai1_chart.html (Unit1) and 

http://www.nrc.gov/NRR/OVERSIGHT/ASSESS/PRAI2/prai2_chart.html (Unit2). 

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