Radioactive Tritium from Monticello Reactor Leaked to the Mississippi River

Image by Minnesota Department of Commerce.

The US Nuclear Regulatory Commission (NRC) has formally apologized for multiple false assurances from its staff that a major leak of radioactive tritium from Xcel Energy’s Monticello nuclear reactor had not reached the Mississippi River — the drinking water source for 20 million people, including, 3.7 million in the Minneapolis/St. Paul metro area.

In opening remarks to an NRC-sponsored public hearing at the Monticello (Minn.) Community Center May 15, 2024, senior NRC Branch 1 Environmental Project Manager Stephen Koenick, made jaws drop around the room when he quashed and corrected the NRC staff’s oft-repeated claims that 820,000 gallons of radioactive tritium-contaminated cooling water, that leaked from the 53-year-old reactor, had not been detected in the Mississippi.

Koenick said, “I would like to take a moment to address and clarify some miscommunication regarding the presence of detectable tritium in the Mississippi River. I know we … reported there [was] no indication [that the] tritium leak made it to the Mississippi. However, … in our Draft Environmental Impact Statement we … conclude there were some very low concentrations of tritium in the Mississippi River.” In this extremely rare and incriminating confession, Koenick went on: “So we apologize for this miscommunication.” (Transcribed from cellphone recording of the hearing.)

This official U-turn and apology from NRC managerial staff over its use of routinized PR-driven claims of “no danger to the public” — in this case regarding a major radioactive leak — should ravage the credibility an arguably industry-captured commission. Nothing it says should be taken at face value.

The NRC’s about-face nullifies months of repeatedly saying to the press, which then duly reported, that no detectable tritium had been found by Xcel’s testing of the Mississippi River. On March 18, 2023, NRC spokesperson Victoria Mitlyng even told the press, “There is no pathway for the tritium to get into drinking water.” Absurdly, even an official NRC email message sent to Nukewatch the same evening of the May 15 public hearing, states: “As far as the Mississippi River, samples taken from the river so far have not shown increased tritium concentrations.”

A week before the formal disavowal, on May 7, 2024, NRC presenters at an NRC-sponsored public hearing, held in the same Monticello community center, repeated on the record that Xcel had found “no detectable levels” of tritium in the Mississippi. Since the massive leak was disclosed in March 2023, Xcel has claimed, as it does in a company website posting (“Monticello Groundwater: Progress on the recovery and treatment of tritium in the groundwater….as of Nov. 18, 2023”): “We test the river regularly for tritium and have not found any, indicating that if it is present, it is at such low levels, and is dispersing so quickly, that it cannot be detected by highly sensitive instruments.”

Xcel’s tritium contamination of the Mississippi has been confirmed by the NRC’s April 2024 “draft Site-specific Environmental Impact Statement” (Draft EIS) regarding Xcel’s request for an extended operating license, and by Xcel’s own 2023 “Annual Radioactive Effluent Release Report”, which says on page 2: “Tritium was detected in newly developed MW-33A [monitoring well-33A] and MW-37A which resulted in MNGP [Monticello Nuclear Generating Plant] reporting an abnormal discharge to the Mississippi River.” Monitoring wells 33A and 37A are the two closest to the river.

Xcel has now, and for a second time, applied to the NRC for an extended operating license which, if granted, would allow the achey, breaky Monticello jalopy to run until the age of 80. No power reactor on earth has ever done so. Such official lying and its protection of corporate contamination of drinking water ought to be scandal enough to cancel any consideration of Xcel’s license extension. Public denunciations or “comments” on the NRC’s Draft EIS on the application are being accepted until June 25. To send yours, see:

John LaForge is a Co-director of Nukewatch, a peace and environmental justice group in Wisconsin, and edits its newsletter.