Source : Tokyo CNN (http://edition.cnn.com/)
Japan Chief Cabinet Secretary Yukio Edano said there is no massive radioactive leakage and the blast at the No. 3 reactor on Monday was caused by a buildup of hydrogen.
Japanese officials have said they are operating under the presumption that there may already be a partial meltdown at reactors No. 1 and No. 3. Authorities have not been able to confirm a meltdown because it is too hot inside the affected reactors to check.
You guys can check it here >> https://inaiputih.wordpress.com/2011/03/15/international-atomic-energy-agency-iaea-update/