Radioactive water leaks at Prairie Island pose 'no risk'

Nearly 4,000 gallons of water containing “small amounts” of tritium and “trace amounts” of other chemicals have been released by Prairie Island nuclear plant since November, Xcel Energy spokeswoman Mary Sandok said Wednesday.

The most recent leak, occurring when 27 gallons of water that had condensed from heating system steam overflowed a holding tank, happened Feb. 3.

A pump failed to regulate levels within the tank, Sandok said, and the water overflowed out a vent pipe and onto the ground. The heating system has been shut down while the cause of the pump failure is investigated and corrected.

The plant notified the Minnesota Pollution Control Agency and the Nuclear Regulatory Commission of the release Monday.

In late November, about 3,900 gallons of water containing small amounts of tritium was released under similar circumstances, Sandok said Wednesday.

That overflow occurred over several days, leading to the larger volume of water released. The most recent release was identified and stopped more quickly, Sandok said.

Neither release posed a threat to the public or employees, Sandok said, adding that the amount of tritium in the released water falls below the U.S. Environmental Protection Agency’s limit for safe drinking water.

The plant monitors groundwater at Prairie Island at about 60 sampling sites both at the plant and off-site, Sandok said. Samples are taken monthly, quarterly or annually, depending on the location, but each site is sampled at least once a year.

The tritium spilled from the holding tank will be diluted by groundwater and decay as it moves toward the nearest groundwater monitoring site, Sandok said, adding that it will take about 15 years for the tritium to reach the site.

Tags: prairie island nuclear plant, mississippi river, environment, minnesota