Prairie Island Nuclear Power Plant Unit 2 in Red Wing, Minn., resumed generating electricity on Monday after a 3 ½-month shutdown to complete a $280 million replacement of two steam generators during a partial refueling, the plant's owner said.

Xcel Energy, based in Minneapolis, said the unit was restored to full power at 2 a.m., after being out of service since Sept. 21. About 1,500 contractors helped the plant's staff replace a third of the fuel along with two steam generators that were 40 years old.

Each of the two units at the plant is refueled about every 18 months, and the utility often completes other major work during such outages.

David Shaffer