Environmental News

Barrier coming to site of Minnesota nuclear plant leak

an aerial map
A map of Xcel Energy's plans for a barrier wall at the Monticello nuclear power plant along the Mississippi River. The barrier will be 40 feet deep and it's length will be 600 feet, and will minimize interaction between ground water and river water.
Courtesy of Xcel Energy

Updated: Aug. 18, 11 a.m. | Posted: Aug. 17, 5:25 p.m.

Xcel Energy says it will construct a metal barrier to keep groundwater from the Mississippi River near the Monticello Nuclear Plant.

The project comes after the plant leaked water containing radioactive tritium last November.

A spokesperson for Xcel said the barrier is another step the company is taking to try to keep the small amount of tritium in the groundwater within the plant boundaries.

The barrier will be 600 feet long and 40 feet deep. It will be about 20 feet from the river’s edge. Construction is expected to begin in the next several weeks, and will take between one and two months to complete.

The leak happened in November 2022, after a broken pipe leaked water containing tritium.

The company said no tritium has been detected in the Mississippi River, but it has been detected at small rates within 30 feet of the river.

Tritium is a mildly radioactive form of hydrogen that occurs naturally in the environment, and also during nuclear power production. The company and the state released a statement earlier this year saying the leak does not present a threat to public health.

Xcel says it's recovered about three-fourths of the leaked tritium. Most of the remaining contamination remains on the plant site.

Correction (Aug. 18, 2023): An earlier version of this story incorrectly identified the material that will be used to build the barrier. It will be made of interlocking metal sheets.