A small fire disrupted the cooling system at an eastern Nebraska nuclear power plant, but regulators say there was no danger of radiation release because the plant has been shut down for refueling.

The Nuclear Regulatory Commission says the fire in a switchgear room was reported Tuesday morning and extinguished by automated systems within less than an hour.

The Omaha Public Power District plant briefly lost its main cooling system for the spent fuel pool, but the temperature of the pool remained at safe levels.

Regulators say OPPD regained cooling ability and didn't have to use any of its backup cooling systems.

The plant has been shut down since April.

Fort Calhoun sits about 19 miles north of Omaha near the Missouri River.