Chief Cabinet Secretary Yukio Edano said Sunday that a hydrogen explosion is possible at the No.3 reactor of Fukushima No.1 nuclear power plant.

At an emergency press conference, Edano said that the reactor could resist the possible blast.

And it will not pose any risk to the health of the evacuees even if the blast occurs, he added.

And there is no new serious problem at the nuclear power plant, said the top government spokesman.

Tokyo Electric Power Co.(TEPOC), operator and owner of the Fukushima plants, has injected sea water into the reactor to prevent it from overheating, said Edano, who acknowledged the core of the reactor may have been deformed due to overheating.

But a meltdown has not occurred, he said.

The No. 3 reactor lost its ability to cool the reactor core earlier in the day, reported the TEPOC.

A hydrogen explosion occurred at the No. 1 reactor at the plant Saturday, blowing away the roof and walls of the building that houses the container of the reactor and injuring four people.