But experts have said it will take years -- perhaps decades -- to fully clean up the worst nuclear disaster since Chernobyl. Hydrogen explosions blew apart the No. 1 and No. 3 reactor housings, while another hydrogen blast is suspected to have damaged the No. 2 reactor, and fires believed caused by heat from the No. 4 spent fuel pool damaged that unit's reactor building...parts of the buildings remain inaccessible because of high radiation levels and debris
The plume of radioactive particles that spewed from Fukushima Daiichi displaced about 80,000 people who lived within a 20-kilometer (12.5-mile) radius of the plant, as well as residents of one village as far as 40 kilometers to the northwest. The government has yet to determine when those evacuated can return to their homes...Japan's main strategy has been to scrape off the top 5 centimeters (2 inches) of topsoil from contaminated areas -- a plan the IAEA found could produce "huge amounts of residual materials"