Chief Cabinet Secretary Yukio Edano was quoted by the Kyodo news agency as saying that the plant operator Tokyo Electric Power Co. confirmed that the blast did not damage the container of the No. 3 reactor and allayed fears that the blast may have caused a massive release of radioactive substance.
Edano said, the possibility is low that massive radioactive materials have spattered. Edano said the blast that blew away the roof and the walls of the building housing the container was similar to an explosion Saturday at another reactor of the same plant, after Friday’s magnitude 9.0 quake.
Other media reports said that the explosion was heard from 40 kilometers away. The top government spokesman said operations to pour sea water into the reactor to cool it down were continuing and the level of pressure in the container was stable.
Japan’s Nuclear and Industrial Safety Agency said wind was not blowing in the area and the radiation level had not significantly risen.
Meanwhile other reports say, the radiation at the plant’s premises today rose over the benchmark limit of 500 micro sievert per hour at two locations.
The hourly amounts are more than half the 1,000 micro sievert to which people are usually exposed in one year.
The seawater were being poured into the plant’s 1 and 3 reactors to help cool their cores, which are believed to have partially melted after part of the fuel rods were no longer covered by coolant water when levels fell following the quake.
Japan’s nuclear agency had earlier declared a state of emergency at another nuclear facility at Onagawa after excessive nuclear radiations were reported there.
Thousands of military personnel and civilians joined hands in a massive search and rescue operation.
Over 1 lakh 80 thousand people have been evacuated from a 20 kms radius from the nuke plant joining over 3.5 lakhs who have already moved out.
The International Atomic Energy Agency is helping the Japanese authorities and monitoring the situation.
UN atomic watchdog IAEA said, radiation levels at the quake-damaged Fukushima nuclear plant are normal. It said in a statement that radiation dose rate measurements observed at four locations around the plant’s perimeter over a 16-hour period on March 13 are all normal.