Federal regulators determined Monticello power plant leak was ‘non-emergency’

Xcel Energy is working to contain a leak of radioactive water at the Monticello Nuclear Generation Plant. While the public was informed of the situation on Thursday, the company alerted the Nuclear Regulatory Commission of the leak months ago.

“We don’t have any danger to drinking water, we don’t have any danger to public health, safety or the environment,” declared Chris Clark, Xcel’s President for Minnesota, North Dakota, and South Dakota. “When this happened, we of course notified the Nuclear Regulatory Commission, we notified state agencies and local authorities.”

In mid-November, an on-site monitoring well right under the plant detected a concerning level of tritium, which is a radioactive form of hydrogen that occurs as byproduct of the reactor.

Clark said the leak was reported to the NRC in November and eventually located on Dec. 19. The company had inventoried more than 170 possible areas of the leak and determined one source.

“It was in a very difficult place to get to, it was literally between two buildings that have a very small space between them,” said Clark. “We actually ended up drilling a hole through concrete wall to get a camera in to determine that actually was a cause of the leak.”

The carbon steel condensate pipe is about four inches in diameter.

“As we’re making nuclear energy, we’re creating steam to turn a turbine,” explained Clark. “Once the steam has done the work of turning the turbine, it goes back through a process to turn into water, or condensate, then is under pressure and returns. It’s a constant loop in a boiling water reactor, so it’s a part of that process.”

The company determined more than 400,000 gallons of water had leaked from the pipe. Xcel has about two dozen monitoring wells in three rings around the property. According to Clark, the wells show the water did not spread beyond the property.

“We’ve started pumping from different wells and we’re able to see we’re having the impact of stopping that water from moving forward and actually pulling it back to the plant and then bringing that tritiated water back up,” he said.

A Nuclear Regulatory Commission report from November designates the event as a “non-emergency.” The federal agency considers an event an emergency if it has a high likelihood of affecting public health and safety or the environment.

A spokesperson for the federal agency told 5 EYEWITNESS NEWS in an e-mail Friday, “The NRC will notify the media and the public through a news release if the agency becomes aware and responds to an issue that can seriously impact plant safety or public health. This was not the case with the tritiated leak at Monticello. Our inspectors assessed the situation and while they continued to closely monitor the plant’ response to the leak, the situation did not pose a threat to plant or public safety.”

“It’s a highly regulated industry,” said Brian Vetter, who is a radiation safety officer and the director of the Department of Radiation Safety at the University of Minnesota. He is not affiliated with the Monticello situation.

Vetter explained he wasn’t concerned initially about a risk to public health when he learned about the leak.

“Tritium is found in nature so it’s a part of the naturally radioactive world,” he said. “It’s a very weak emitting isotope and by weak, I mean the particle that it emits doesn’t have very much energy.”

“We are wearing our shield when it comes to protecting us because the layer of dead skin cells we have it’s extremely thin but it’s enough to stop that emission of the beta particle,” he added.

The concern, he said, is if it’s ingested.

In a press release on Thursday, the MPCA noted, “There is no evidence at this time to indicate a risk to any drinking water wells in the vicinity of the plant.”

Xcel Energy has recovered about 25% of the water that leaked. The diversion process continues.

“We’ll end up pumping up more water than actually leaked into the ground to make sure we’ve contained all of the tritium here,” said Clark. “We’ll pump it out of those wells and we’re storing it in temporary storage tanks. We’ll likely build some permanent structures and then we’ll work to either re-use water in our normal plant processes or we’ll work with the state agencies to determine other ways we can process that water.”

Xcel says it conducts ‘regular, robust’ inspections and closely monitors water at the plant, so it can identify and resolve any issues.

The Minnesota Department of Health says its doing water monitoring in the river and in wells to ensure no radiation spreads from the plant.

The company has yet to determine how long the leak was happening before it was detected.

Clark said they plan to cut the pipe out of the wall and send it to a lab to understand how it failed and get a better idea of the timing.

“The well that detected this is right under the plant so it should be relatively close in time but whether that was days, weeks, or months — we’ll find out through that root cause analysis,” said Clark.

Monticello Mayor Lloyd Hilgart provided 5 EYEWITNESS NEWS the following statement on Friday:

The City of Monticello learned about the extent of the water leak at the Monticello Plant at the end of February 2023.

Since then, we have been working with Xcel and state and federal regulating agencies to understand the scope of the event, remediation, and any community impact. We have been and will continue to gather information to responsibly inform our community and have been requesting information be shared.

Though the Xcel plant is within our community, the City of Monticello does not have the authority to govern the nuclear plant. As we’ve noted, the federal and state regulating agencies determine the appropriate governmental responses to incidents at the Xcel nuclear plant, including any emergency response, remedial actions and public or media releases. If state or federal oversight agencies determine that there is any potential or actual impact to the City’s drinking water supply or infrastructure the City will immediately notify the public with assistance from these agencies. For now, we will continue to advocate for our community and participate as appropriate at the city-level.

Residents with general questions, can contact Steve Mikkelson at MPCA (stephen.mikkelson@state.mn.us or 218-316-3887). Residents that have concerns about private wells, contact Jennifer Weier at MN Department of Health (Jennifer.weier@state.mn.us or 651-201-3658).

We encourage members of the public to use the resources and contact information provided by Xcel Energy (residents can click on the “contact” button on Xcel’s website) for questions about the leak and the plant. City leaders will continue to participate in the process on behalf of the community and share information as it becomes available.