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.

Despite the crisis in Japan, Mr. Kan indicated Sunday that his government was not rethinking the nation’s energy policy. There had been speculation that the government might seek to shut down more nuclear plants after Mr. Kan requested last week that the Hamaoka nuclear plant in central Japan be temporarily closed because of safety concerns.

Mr. Kan told reporters on Sunday that he would not seek to close any more of Japan’s 54 nuclear reactors. He said the Hamaoka plant, 125 miles west of Tokyo, was “a special case” because it sat atop a major fault line. Government seismologists say there is an almost 90 percent chance of a major earthquake on the fault line within the next 30 years.