Japan said today that decommissioning the tsunami-wrecked reactors at Fukushima could take as long as 40 years, with melted nuclear fuel possibly stuck where it is for a quarter of a century.
A roadmap produced by the government and plant operator Tokyo Electric Power (TEPCO) envisages engineers will use much of the next 10 years just trying to work out how to get at the fuel, which has partly eaten through its containment vessels.
Underlining the challenges involved in dealing with the disaster, the plan says that as-yet uninvented technology will be key to safely disposing of the waste left behind by the world's worst nuclear accident since Chernobyl.
"Each and every one of the steps toward decommissioning currently poses many technological challenges," said Goshi Hosono, the government minister with responsibility for dealing with the Fukushima disaster.
"We expected extremely difficult work to remove fuel debris [from the reactors]. We must accelerate work to develop technologies, particularly remote control robots," he told reporters.
"We will gradually make progress by assessing both the situation on site and the state of research and development work," he said.
The unveiling of the plan comes days after Prime Minister Yoshihiko Noda announced the stricken reactors on Japan's tsunami-ravaged northeast coast had reached a state of "cold shutdown".
