Xcel Energy's nuclear power plant in Monticello is back online after four months.
The plant was shut down for upgrades and to increase its power output by 12 percent, to 671 megawatts. Xcel is still working to get approval from the Nuclear Regulatory Commission to operate the plant at the increased level. Right now the plant produces enough electricity to power 450,000 homes.
Last month, Xcel filed documents with the Public Utilities Commission that showed the estimated cost for the upgrade was $640 million -- double what the company said the project would cost in 2008.
Xcel is asking the state to approve a rate increase for its customers in part to pay for the nuclear plant upgrades. The state takes up the request Tuesday at a hearing in St. Paul, Minn., and is expected to issue a ruling later this week.