The stricken Fukushima Dai-ichi nuclear plant is the world's most complex and costly industrial clean-up. The first three of Fukushima Dai-ichi's six reactors melted down in March 2011 and the fourth was damaged, tepco's early guess was that decommissioning would take 30-40 years. That is certainly optimistic. Engineers are grappling with problems with little precedent. Akira Ono, the plant manager, says cameras have begun peeking into the first reactor to check the state of 100 tonnes of molten fuel. A robot needs to be developed to extract the fuel. Last October the utility pushed back the start of this removal work by five years, to 2025. Dale Klein, a former chairman of America's Nuclear Regulatory Commission, says that the schedule for decommissioning the plant is pure supposition until engineers figure out how to remove all the fuel. One victory for engineers is with reactor four. Late last year the last of 1,535 highly toxic fuel rods was plucked from the spent-fuel pool a year ahead of schedule. The fear was that the complex could not withstand another strong earthquake.
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