Minnesota nuclear plant shuts down again after new radioactive water leak detected.

Xcel Energy's nuclear plant in Monticello, Minnesota, is temporarily shutting down after discovering a smaller leak of tritium-contaminated water. The plant had previously leaked 400,000 gallons of radioactive water last year. The new leakage is estimated to be in the "hundreds of gallons" and "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," Xcel Energy said. The length of the shutdown has not yet been determined but should not impact customers' electric service.