Still, a partial meltdown in the unit is "highly possible," he told reporters. Later, Unit 3 also began to experience problems.Ĭhief Cabinet Secretary Yukio Edano said operators released slightly radioactive air from Unit 3 Sunday, while injecting water into it as an effort to reduce pressure and temperature to save the reactor from a possible meltdown. At first, the Unit 1 reactor was in trouble with an explosion destroying the walls of the room housing it. The quake and tsunami damaged three reactors at the Fukushima Daiichi nuclear plant, which lost the cooling functions necessary to keep the fuel rods functioning properly. In this video image taken from NTV Japan, smoke rises from the Fukushima Daiichi nuclear power plant's Unit 1 in Okumamachi, Japan. The official count of the dead was 763, but the government said the figure could far exceed 1,000. Geological Survey has measured the quake at magnitude 8.9, and that number remained unchanged Sunday. Japan dealt with the nuclear threat as it struggled to determine the scope of Friday's twin disasters when the earthquake - which the Japanese Meteorological Agency has now upgraded to magnitude 9.0 from 8.8, the most powerful in its recorded history - was followed by a tsunami that ravaged its northeastern coast with breathtaking speed and power.
A complete meltdown would release uranium and dangerous byproducts into the environment that can pose serious health risks. Some 170,000 people have been ordered to evacuate the area covering a radius of 20 kilometres around the plant in Fukushima.Ī meltdown refers to a very serious collapse of a power plant's systems and its ability to manage temperatures. A partial meltdown was likely under way at a second nuclear reactor, a top Japanese official said Sunday, as authorities frantically tried to prevent a similar threat from a nearby unit following a catastrophic earthquake and tsunami.