Fukushima Daiichi nuclear disaster (Unit 3 Reactor) 13 March an official of the Japan Nuclear and Industrial Safety Agency (NISA) told at a news conference that the emergency cooling system of Unit 3 had failed, spurring an urgent search for a means to supply cooling water to the reactor vessel to prevent a meltdown of its reactor core. At 05:38 there was no means of adding coolant to the reactor, owing to loss of power. Work to restore power and to vent excessive pressure continued. At one point, the top three meters of the uranium/mixed oxide (MOX) fuel rods were not covered by coolant. At 07:30 JST,
Fuel element failure core, into the rest of the primary cooling circuit, increasing contamination levels there. In the EU, some work has been done in which fuel is overheated in a special research reactor named PHEBUS. During these experiments the emissions of radioactivity from the fuel are measured and afterwards the fuel is subjected to Post Irradiation Examination to discover more about what happened to it. Fuel element failure A fuel element failure is a rupture in a nuclear reactor's fuel cladding that allows the nuclear fuel or fission products, either in the form of dissolved radioisotopes or hot particles, to enter the