Xcel Energy's Prairie Island nuclear plant is undergoing a routine refueling outage at one of its two reactors.
A crew of 750 plant workers and 600 contract workers, will replace one third of the fuel rods, and do other inspections and repairs over the next 4 to 6 weeks.
Xcel Energy spokeswoman Mary Sandok said concern over problems at a nuclear plant in Japan did not influence the timing of the Prairie Island maintenance. She said these outages are planned years in advance:
"We always do our refueling outages in seasons when the power demand is not so high, so that's why you see them in spring and fall," Sandok said. "We do not do them in the summer when we need all of our plants running."
Prairie Island's two nuclear generators supply a fifth of the state's electricity.