MINNEAPOLIS (AP) -- Xcel Energy Inc. has shut down two of Minnesota's three nuclear reactors.
The Monticello plant had been operating at 10-percent power since the weekend, and operators shut down Prairie Island's Unit 1 plant Tuesday.
Xcel says both shutdowns were done safely. The Minneapolis-based utility says neither resulted in a release of radioactive materials and did not pose a danger to the public or plant employees.
At Prairie Island, a test found emergency diesel generators were inoperable.
Minnesota Public Radio News reports workers closed the Monticello plant after discovering leakage which apparently was caused by a failing gasket on a pipe flange.
Xcel says the leaked material was contained within the containment structure.
The company is buying power on the open market, and says repairs will not take long.