“We sincerely apologize for causing troubles,” Katsumata said. “We are doing our utmost to prevent the crisis from further worsening.”

Katsumata said he was not sure when the tens of thousands who had been forced to flee their homes because of the crisis could go back, but Trade Minister Banri Kaieda said some could return home within six to nine months.

“Of course, some people will be unable to return home, but we will keep everyone informed,” he said, adding that the government hoped TEPCO could contain the radiation sooner than the schedule announced Sunday calls for.

TEPCO said it needs three months to achieve ‘‘steady reduction’’ in radiation, and an additional three to six months to control radioactive emissions and curb radiation substantially.

It said it is addressing the immediate challenges of preventing hydrogen explosions at the Nos. 1 to 3 reactors and emission of water contaminated with high-level radiation from the No. 2 reactor.

It also said it will put special covers on the heavily damaged buildings of the Nos. 1, 3 and 4 reactors.

The nuclear plant has been crippled by the devastating March 11 earthquake and subsequent tsunami, with the resulting damage causing radioactive materials to be emitted into the environment and forcing residents near the plant to be evacuated.
 
The company is focusing on cooling the reactors and spent fuel pools, decontaminating water that has been contaminated by radiation, mitigating the release of radiation into the atmosphere and soil and measuring and reducing the amount of radiation effecting the evacuation area, he said.
 
TEPCO Vice President Sakae Muto said that in addition to covering the reactor buildings, the company will also work with authorities to decontaminate areas affected by the radiation.

Visiting U.S. Secretary of State Hillary Rodham Clinton said that U.S. experts will analyze TEPCO’s restoration plan.