400,000 Gallons of Contaminated Water Leaked From Minnesota Nuclear Plant

A nuclear plant in Minnesota has leaked around 400,000 gallons of water contaminated with tritium, the Minnesota Pollution Control Agency (MPCA) reported Thursday. 

The leak was first detected by the plant’s owner Xcel Energy in November of 2022, but state officials only informed the public last week. 

“Our top priority is protecting residents and the environment, and the MPCA is working closely with other state agencies to oversee Xcel Energy’s monitoring data and cleanup activities,” MPCA assistant commissioner for land and strategic initiatives Kirk Koudelka said in a statement. “We are working to ensure this cleanup is concluded as thoroughly as possible with minimal or no risk to drinking water supplies.”

Tritium is a radioactive form of hydrogen, but the radiation it emits is on par with common food items, Xcel Energy said in a statement. However, exposure to massive amounts can increase cancer risk, according to the Canadian government. It is naturally present in the atmosphere, but is also a common byproduct of nuclear energy, MPCA said. 

Xcel Energy first noticed the leak when groundwater testing turned up unusual results and sourced it to a leaky pipe connecting two buildings in its Monticello nuclear plant. The leak was contained before it contaminated either the Mississippi River or local drinking water sources. So far, Xcel said it had cleaned up around 25 percent of the leak and would continue working into the next year. 

“We have taken comprehensive measures to address this situation on-site at the plant. While this leak does not pose a risk to the public or the environment, we take this very seriously and are working to safely address the situation,” Xcel Energy–Minnesota, North Dakota and South Dakota President Chris Clark said in a statement posted on the company website.. “We continue to gather and treat all potentially affected water while regularly monitoring nearby groundwater sources. We will continue to partner with local groundwater specialists, and we remain in close cooperation with state and federal regulators and our local community throughout the remediation effort.” 

The company reported the leak to both state officials and the Nuclear Regulatory Commission (NRC) as well as the state on Nov. 22 of last year. However, the MPCA told The Associated Press that they waited until they had more information to publicize it. 

“We knew there was a presence of tritium in one monitoring well, however Xcel had not yet identified the source of the leak and its location,” MPCA spokesman Michael Rafferty told the news agency. “Now that we have all the information about where the leak occurred, how much was released into groundwater, and that contaminated groundwater had moved beyond the original location, we are sharing this information.”

In general, the NRC said that, while tritium spills occur every so often at nuclear plants, they usually either remain contained within the plants’ property limits or involve amounts too minimal to pose a public health threat. 

Nuclear energy was long opposed by environmental groups, but climate experts have begun to embrace it as an alternative to fossil fuels. The Biden administration announced $1.2 billion to extend or restart the life of aging nuclear plants in early March. Excel Energy has promised to provide entirely carbon-free electricity to its customers by 2050. Part of its plan for doing so in the Upper Midwest includes extending the life of the Monticello nuclear plant by 10 years to 2040. The Minnesota Public Utilities Commission approved the plan in 2022.

“The approved plan means more than 80% of customers’ electricity will be carbon free by the end of the decade, with more than half coming from wind and solar,” the company said on its website. “The elements of this plan all work together to achieve these aggressive clean energy targets while protecting reliability and affordability for customers.”