During the outage which began on 23 October 2012, the station’s staff along with 600 workers completed maintenance tasks to prepare the reactor for its next operating cycle. One-third of the unit’s fuel had been replaced.

The company said each of the two 550MW capacity reactors at Prairie Island Nuclear Generating Plant is refueled about once every 18 months.

The Prairie Island plant, which is owned and operated by Xcel Energy, generates enough electricity to power about one million homes in the region.

Xcel Energy said the Prairie Island and Monticello nuclear stations are among its lowest-cost sources of generation on a per megawatt hour basis and they do not produce any greenhouse gas emissions.