Xcel Energy to take Monticello nuclear plant offline to fix tritium leak

Temporary shutdown of plant not expected to impact electric service

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MINNEAPOLIS – Xcel Energy will begin powering down its Monticello Nuclear Generating Plant tomorrow to allow it to more quickly perform the repairs needed to permanently resolve a leak of water containing tritium at the plant. The company does not anticipate any impacts to customers’ electric service from powering the plant down early.

“While the leak continues to pose no risk to the public or the environment, we determined the best course of action is to power down the plant and perform the permanent repairs immediately,” said Chris Clark, president of Xcel Energy–Minnesota, North Dakota and South Dakota. “We are continuing to work with and inform our state, federal, city and county leaders in the process.”

After identifying the source of the leak late last year, which poses no health and safety risk to the local community or the environment, Xcel Energy implemented a short-term solution to capture water from the leaking pipe and reroute it back into the plant for re-use. This solution was originally designed to prevent any new tritium from reaching the groundwater until the company could install a replacement pipe during a regularly scheduled refueling outage in mid-April.

However, monitoring equipment at the plant Wednesday indicated a small amount of new water from the original leak had reached the groundwater. Upon investigation, operators discovered the temporary solution was, over the past two days, no longer capturing 100% of the leaking water. The new leakage — anticipated to be in the hundreds of gallons, a much smaller amount of water than previously leaked — will not materially increase the amount of tritium the company is working to recover and does not pose any risk to health or the environment.

Tritium is a compound that is naturally present in the environment and is commonly created in the operation of nuclear power plants. It emits low levels of radiation, similar to everyday materials people use and the food we all eat.

Ongoing monitoring from over two dozen on-site monitoring wells confirms that the leaked water remains fully contained on-site and has not been detected beyond the facility or in any local drinking water. State agencies continue to monitor Xcel Energy’s remediation work to ensure the continued safety of the local community and surrounding environment. To date, Xcel Energy has recovered about 32% of the tritium released and will continue recovery over the course of the next year.

The schedule for resuming operation at the plant is still to be determined. The plant is also scheduled to begin its refueling process this spring, with maintenance and construction projects taking place that can only be completed when the plant is not operating. Refueling and plant maintenance will improve the reliability of equipment at the plant and help to ensure that Monticello continues to provide safe, clean, and reliable power to the region.

Members of the public who have questions about the leak or the plant powering down early are invited to attend one of two open houses at the Monticello Community Center: Friday, March 24 (10 a.m. to 1 p.m.) and Monday, March 27 (5 p.m. to 8 p.m.).