Officials identified a radioactive leak at a Minnesota nuclear power plant last week, shutting the plant down over the weekend to begin repairs. While the contaminated water leaking from Xcel Energy’s Monticello Nuclear Generating Plant does not pose any risk to the public or environment, the plant shutdown caused a dramatic temperature change in the Mississippi River that killed 230 fish. “The fish kill is unfortunate but not unexpected given the significant temperature change that can occur when warm water from the plant stops flowing to the river during a shutdown in operations,” the Minnesota Pollution Control Agency said in a statement to CBS News. Officials plan for the plant to resume operations later this week. This incident follows a November leak at the same plant, in which 400,000 gallons of water containing tritium contaminated the river.