A leak of 400,000 gallons (1.5 million liters) of radioactive water from a nearby nuclear power plant in Minnesota is being closely watched by authorities.
The incident was “completely controlled on-site and has not been discovered outside the facility,” according to Xcel Energy, the utility that manages the plant.
There is no imminent public health concern, according to state officials.
State officials found the breach in late November, but they did not alert the public until Thursday.
Tritium, a typical byproduct of nuclear reactor activities, is present in the water.
According to the federal Nuclear Regulatory Commission, tritium is a naturally occurring radioactive isotope of hydrogen that produces a weak kind of beta radiation that does not penetrate human skin and does not travel very far in air (NRC).
Tritium spills occasionally happen at nuclear power facilities, although they are normally localized locally and infrequently endanger public safety or health, according to the NRC.
At its Monticello plant, Xcel first noticed the leak on November 21 from a conduit between two structures. Minneapolis, the state’s largest city, is located roughly 35 miles (56 km) upstream along the Mississippi River from the plant.
The business said that the next day, it had informed the NRC and the state.