The Nuclear Regulatory Commission (NRC) said March 4 it has put the Xcel Energy (NYSE:XEL) Monticello nuclear plant in Minnesota under increased oversight although it has decided not to categorize it as a facility with multiple and systematic problems.
Monticello is run by Xcel’s Northern States Power – Minnesota and is located in Monticello, Minn., 30 miles northwest of Minneapolis. The plant is a single-unit boiling water reactor (BWR) with a nameplate capacity of 685 MW.
NRC was already looking at the nuclear plant over problems with flood prevention strategy at the station in 2013 when Monticello was issued a significant security finding on Feb. 26.
“While the details of this [security] issue are not publicly available, it is important to note that the plant has corrected the situation,” NRC said in a March 4 news release.
Xcel Energy agreed to “an independent safety culture assessment with a focus on human performance,” at Monticello, according to NRC documents.
The NRC uses color-coded inspection findings and performance indicators to assess nuclear plant performance. The colors go from “green” to “white,” “yellow,” and “red,” commensurate with the safety significance of the issue. 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 another column results in an increased level of NRC oversight and inspections. If the NRC loses confidence in the plant’s ability to perform safely, the plant will shut down and move to column 5.
Monticello has been in Column 3 of the performance matrix since 2013 due to a yellow finding related to weaknesses in the external flooding strategy. The results of two recent inspections demonstrated that the plant has taken effective actions to resolve the issues that led to the violation. The results of the inspection, which focused on the flooding issue, indicated a reversal in negative trends that led to the violation. The other inspection, which assessed the plant’s ability to identify and resolve problems, also showed improvement in the plant’s performance.
Back in 2013, the Monticello plant was assessed a yellow finding in connection with the site’s ability to combat an external flooding event.
On Feb. 26, the NRC issued Monticello a greater than green security finding identified in the fourth quarter of 2014. By the NRC’s normal process, this finding, aggregated with the yellow finding, would result in Monticello’s placement in Column 4 in the fourth quarter of last year.
NRC, however, will deviate from its normal process and place Monticello in Column 2 of the performance action matrix based on the fact that the flooding issue has been resolved; there have been no recent indications of new significant problems; and improvements in performance. The greater than green security finding warrants a follow-up inspection, which will take place after the plant has had the opportunity to address the issues that caused the incident. In addition, the NRC will also perform an inspection focused on persistent human performance concerns at the plant.
“The NRC acknowledges that your staff has taken action to reverse the performance trends that led to these findings,” NRC said. “Despite those actions, human performance related issues continue to occur at [Monticello],” the agency said.
“Plants in Column 4 tend to have broad and systematic performance issues across multiple areas of plant operation. Our recent inspections demonstrate that Monticello’s performance does not warrant its placement in Column 4,” said NRC Region III Administrator Cynthia D. Pederson. “However, we will make sure the plant can sustain the improvements made so far and has resolved the security finding.”