Fish death near leaking US nuclear reactor explained by regulator

A state regulator in Minnesota said hundreds of fish were killed after a nuclear power plant was forced to shut down due to a radioactive leak. The Minnesota Pollution Control Agency (MPCA) said an estimated 230 fish were killed not by radioactive contamination, but as a result of the shutdown, which was initiated last Friday after another leak was discovered at the Xcel Energy Monticello Nuclear Generating Plant near Minneapolis. The affected animals include bass, channel catfish, common carp, and one or more species of sucker fish. The plant was taken offline to allow work crews to address the leak, but a temporary fix failed, leading to further contamination of the land around the facility. Xcel Energy reported that hundreds of gallons of contaminated water had escaped since the first repair.

The contaminated water carries the radioactive isotope tritium, 400,000 gallons of which poured into the ground from a broken pipe before the leak was noticed last November. The plant operator and local government were aware of the issue for months, but the public was not informed until mid-March. The only way it can affect people is if they breathe it in or drink tritiated water. Xcel said it has fixed the latest leak, but it is unclear when the plant will be back online. Xcel has "enough margin" to supply customers.