Authorities were bracing today for a possible meltdown at a nuclear reactor crippled by Friday's massive earthquake.
Two damaged reactors at the Fukushima Daiichi nuclear power plant had lost cooling ability. Because of the overheating, a meltdown was possible at one of the reactors, said Ryohei Shiomi, an official with Japan's nuclear safety commission.
But even if there was a meltdown, it wouldn't affect humans outside a 6-mile radius, he said today.
In all, Japan declared states of emergency for five nuclear reactors at two power plants on Friday.
Operators at the Fukushima Daiichi plant's Unit 1 scrambled ferociously to tamp down heat and pressure inside the reactor after the quake and tsunami cut off electricity to the site and disabled emergency generators, knocking out the main cooling system.