400,000 gallons of radioactive water leaked in November, Minnesota utility company says -

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An electric utility company announced Thursday, March 17, 2023 that one of its Minnesota plants leaked 400,000 gallons of radioactive water last November 2022.

The leak of water containing tritium from Xcel Energy’s Monticello nuclear power plant “poses no health and safety risk to the local community or the environment,” the Minneapolis-based utility said in a statement. Monitoring efforts confirm the leaked water “is fully contained on-site” and has not been detected in any local drinking water, according to Xcel Energy.

The leak came from a pipe between two buildings and was detected by routine groundwater monitoring systems at the Monticello Nuclear Generating Plant in late November. The plant is located on the Mississippi River, about 35 miles northwest of Minneapolis.

Since then, Xcel Energy has been pumping groundwater, as well as storing and processing the contaminated water, which the company said contains tritium levels below federal thresholds. Xcel Energy said it has recovered about 25% of the spilled tritium so far.

“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,” Chris Clark, president of Xcel Energy-Minnesota, North Dakota and South Dakota, said in the statement.

Why was the leak not immediately made public?

Xcel Energy said it notified the federal Nuclear Regulatory Commission and the state on Nov. 22, the day after it confirmed the leak. But it was not made public until Thursday.

“We understand the importance of quickly informing the communities we serve if a situation poses an immediate threat to health and safety,” Xcel Energy said in a statement. “In this case, there was no such threat.”

State officials also said they waited to get more information about the leak before making it public.

“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,” Minnesota Pollution Control Agency spokesman Michael Rafferty said.

“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,” he said.

What happens next?

Xcel Energy said it is diverting the water to an in-plant water treatment system in order to prevent additional water from leaking. The company said it plans on installing a permanent solution in spring 2023.

Crews inspected piping in all locations where a leak could occur to make sure no other parts of the facility were having the same issue. They will also examine the pipe that leaked in a laboratory to help understand why the leak took place.

Xcel Energy is also considering building above-ground storage tanks to store the contaminated water it recovers.

What is tritium?

A radioactive isotope of hydrogen, tritium occurs naturally in the environment and is a common byproduct of nuclear plant operations, according to the NRC. It emits a weak form of radiation that does not travel very far in the air and cannot penetrate human skin.

“Everyone is exposed to small amounts of tritium every day because it occurs naturally in the environment and the foods we eat,” the agency said.

While nuclear plants spill tritium from time to time, the NRC said the leaks usually remain limited to the plant property or involve low offsite levels that do not affect public health or safety. (source)

Contributing: The Associated Press

Contact Christine Fernando at [email protected] or follow her on Twitter at @christinetfern.