Hugh Pickens writes "The Washington Post reports that the US is urging Americans who live within 50 miles of Japan's earthquake-damaged Fukushima Daiichi nuclear power plant to evacuate as Gregory Jaczko, chairman of the Nuclear Regulatory Commission, said that no water remains in a deep pool used to cool spent fuel at the plant and that radiation levels there are thought to be 'extremely high.' Jaczko's testimony before the House Energy and Commerce Committee suggests that damage to the plant is worse than the Japanese government and the plant's operator, Tokyo Electric Power Co., has acknowledged. On Tuesday, the company said water levels in three of the site's seven fuel pools were dropping, but did not say that the fuel rods themselves had been exposed. Left exposed to the air, the fuel rods will start to decay and release radioactivity into the air and lack of water in at least one spent-fuel pool sparked fears of a worst-case scenario: the fuel could combust. 'If there's no water in there, the spent fuel can start a fire,' says Eric Moore, a consultant to the Nuclear Regulatory Commission on nuclear plant design and safety issues. 'Once you have that fire, there's a high risk of radiation getting out, spewed by the fire.' The power company says a reduced crew of 50 to 70 employees — far fewer than the 1,400 or more at the plant during normal operations — had been working in shifts to keep seawater flowing to the three reactors now in trouble. Their withdrawal on Wednesday temporarily left the plant with nobody to continue cooling operations."