U.S. Calls Radiation ‘Extremely High’ and Urges Deeper Caution in Japan

[tekisui]

Source: New York Times

WASHINGTON — The chairman of the United States Nuclear Regulatory Commission gave a significantly bleaker appraisal of threat posed by the Japanese nuclear crisis than the Japanese government, saying on Wednesday that the damage at one crippled reactor was much more serious than Japanese officials had acknowledged and advising to Americans to evacuate a wider area around the plant than ordered by the Japanese government.

Gregory Jaczko, the chairman of the commission, said in Congressional testimony that the commission believed that all the water in the spent fuel pool at the No. 4 reactor of the Fukushima Daiichi Nuclear Power Station had boiled dry, leaving fuel rods stored there completely exposed. As a result, he said, “We believe that radiation levels are extremely high, which could possibly impact the ability to take corrective measures.”

If his analysis is accurate and Japanese workers have been unable to keep the spent fuel at that inoperative reactor properly cooled — covered with water at all times — radiation could make it difficult not only to fix the problem at reactor No. 4, but to keep workers at the Daiichi complex from servicing any of the other crippled reactors at the plant.

Mr. Jaczko said radiation levels may make it impossible to continue what he called the “backup backup” cooling functions that have so far prevented full nuclear meltdowns at the other reactors. Those efforts consist of dumping water on overheated fuel and then letting the radioactive steam vent into the atmosphere.

more: http://www.nytimes.com/2011/03/17/world/asia/17nuclear.html?_r=1