Unknown damage delays Fukushima cleanup plan
It is delaying by three more years the removal of radioactive fuel rods stored at two of the three reactors damaged in the 2011 disaster.
Six and a half years since a massive earthquake and tsunami struck the plant on Japan's northeastern coast, the amount of contaminated water that must be pumped out and treated every day has decreased significantly, and remote-controlled robots have provided a limited view of melted fuel debris inside the reactors.
Still, the exact location of the melted fuel is largely unknown and robots that can withstand the high radiation for prolonged work there are still being developed.
Among the highest risks at the plant are 1,573 fuel rod units, each consisting of dozens of fuel rods, which are cooled with water in storage pools that are not enclosed within the reactor buildings.
The plant operator, Tokyo Electric Power Co., had planned to start moving them to safer storage by the end of fiscal 2020, but the latest plan says three more years are needed for reactor Units 1 and 2.
Including delays made in earlier revisions, the fuel rod removal plan is now up to six years behind schedule.
Removal at the Unit 3 reactor is set to start next year and is expected to take about two years to finish.
Naohiro Masuda, TEPCO's Fukushima Dai-ichi plant decommissioning chief, said the delay results from previously unknown damage in the storage pool areas and the need for more radioactive decontamination.
He acknowledged that the 30-40-year cleanup plan "may not sound convincing because of all the unknowns and we haven't found most of the melted fuel" inside the reactor cores.
But he said it's important to set a target for developing the technology and work toward that goal.
The decommissioning plan, the second revision approved since the disaster, still calls for the removal of the melted nuclear fuel inside the reactors to start in 2021, based on recent findings on more efficient methods.