TOKYO — Japan remains committed to nuclear power despite the crisis at the Fukushima Dai-ichi Nuclear Power Station, Prime Minister Naoto Kan indicated Sunday, as workers moved closer to repairing the crippled plant by opening the doors of a damaged reactor building.

The move is intended to air out the building that houses Reactor No. 1 to ensure that radiation levels are low enough to allow workers to enter. The plant’s operator, the Tokyo Electric Power Co., said the procedure would release little radiation into the atmosphere because an air filtering system installed last week had already removed most of the dangerous particles.

Eight hours after the doors were opened, officials said, workers entered the building to test radiation levels. The next step is to begin replacing the reactor’s cooling system, which was destroyed by the tsunami on March 11.

The company has said it will take at least six months to stabilize the plant, in which three of the six reactors were damaged by a magnitude-9.0 earthquake and tsunami. Hydrogen explosions spewed radiation into the atmosphere, causing the worst nuclear disaster since the 1986 Chernobyl accident in Ukraine.

There had been speculation that the government might seek to shut down more nuclear plants after Kan requested last week that the Hamaoka nuclear plant in central Japan be temporarily closed because of safety concerns.