Xcel: Monticello leak fixed, nuclear plant will restart in next week

Electrical lines and towers frame a power plant
The Xcel Energy nuclear generating plant near Monticello, Minn., is pictured on Friday.
Ben Hovland | MPR News

Xcel Energy officials said on Tuesday crews have repaired a leak at the Monticello nuclear plant, and the plant will resume producing power in the next week.

The company temporarily shut down the plant late last week, after monitoring equipment detected more radioactive tritium was leaking into groundwater. A short-term fix to catch the contaminated water from an earlier, larger leak last November had failed.

The plant fully powered down early Saturday morning. It will be returned to service in the next week, but powered down again in mid April for a previously scheduled refueling outage, Xcel spokesperson Theo Keith said.

Xcel and state officials have said the leak did not pose any threat to public health, safety or the environment.

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Monitoring underway

The Minnesota Pollution Control Agency said it, along with the state Department of Health, is monitoring samples taken from groundwater wells and has no evidence that the tritium has reached the Mississippi River or contaminated drinking water sources.

As a precaution, the city of Monticello is working with a private vendor to test samples from its five municipal wells for tritium.

“While city officials are confident in the agencies and the science showing the tritiated water has not left the Xcel Energy site, we want to ensure the public feels the same confidence,” said Communications Specialist Haley Foster in an email. 

She said the city would notify the public when the test results are available.

Drop in water temperature causes fish kill near plant

On Monday, authorities said fluctuating water temperatures in the Mississippi River following the temporary shutdown killed more than 200 fish.

The plant continuously draws water from the Mississippi for cooling steam and equipment, then returns the water, warming the river and keeping fish active. When the plant is taken offline, the river cools down, and fish are affected by the change in water temperature.

As of Monday afternoon, at least 230 fish had died in the Mississippi near the plant, including bass, channel catfish, common carp and suckers. Xcel and the Minnesota Pollution Control Agency said the fish kill is not the result of tritium. 

“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 shut down in operations,” the MPCA stated.