Monticello nuclear plant back online

Xcel Energy said Monday that its Monticello nuclear power plant is back in service after a two-week outage for repairs.

The plant 45 miles northwest of the Twin Cities was gradually ramped up to its 600-megawatt output last week after workers repaired a heat exchanger in the reactor coolant system and completed other maintenance, the utility said.

The plant was shut down Jan. 17 when the heat exchanger leaked coolant into other pipes inside the boiling-water reactor's containment structure. No radiation was released, Xcel said. The exchanger was not among the equipment that had been replaced during a five-year upgrade completed last year.

Xcel, based in Minneapolis, said testing has resumed to run the upgraded reactor at its new, higher output, 671 megawatts. That should happen later this year, Xcel said. The plant now generates enough electricity to power nearly 500,000 homes.

David Shaffer • 612-673-7090 @ShafferStrib