The chief of the Fukushima nuclear power station has admitted that the technology needed to decommission three melted-down reactors does not exist, and he has no idea how it will be developed.

In a stark reminder of the challenge facing the Japanese authorities, Akira Ono conceded that the stated goal of decommissioning the plant by 2051 may be impossible without a giant technological leap. “There are so many uncertainties involved. We need to develop many, many technologies,” Mr Ono said. “For removal of the debris, we don’t have accurate information [about the state of the reactors] or any viable methodology for that. But two hundred years ago, nobody would have imagined mobile phones — they wouldn’t have imagined that you could communicate with someone far