Over to Japan, the country's nuclear safety agency says workers have entered one of the damaged reactor buildings at the crippled Fukushima Dai-ichi nuclear power plant for the first time since it was hit by an explosion following the devastating earthquake and tsunami.

The plant's operator TEPCO says two workers entered the reactor building for ten minutes around 11.30 this morning,and were exposed to 2 to 3 millisieverts of radiation.

The workers connected ventilation equipment in Unit one in an attempt to absorb radioactivity from the air inside the building.

Hirota Oyama, TEPCO Spokesman, said, "We just received this information. Operators started construction at noon at the plant Unit one and successfully connected the ventilation equipment at 15.08 today."

TEPCO also says in a report there's no possibility of another hydrogen explosion due to progress in filling the containment vessel.