TOKYO (AP) – Too little is known about the molten fuel inside the damaged reactors of the wreckage of the Fukushima nuclear power plant, even a decade after the disaster, to be able to say whether its decommissioning can be completed d ‘By 2051 as expected, a UN nuclear agency an official said on Friday.
“Honestly speaking, I don’t know, and I don’t know if anyone knows,” said Christophe Xerri, head of a team at the International Atomic Energy Agency reviewing the progress of cleaning up the factory.
He urged Japan to speed up reactor studies to achieve a better long-term understanding of the decommissioning process.
A massive earthquake and tsunami in March 2011 destroyed cooling systems at the Fukushima plant in northeastern Japan, causing three reactors to melt in the worst nuclear disaster since the Chernobyl accident in 1986 The Japanese government and utility officials say they hope to complete its decommissioning within 30 years, although some experts say that is too optimistic even if a full decommissioning is possible.
The biggest challenge is removing and managing highly radioactive fuel debris from the three damaged reactors, said Xerri, director of the IAEA’s Division of Nuclear Fuel Cycle and Waste Technology.
“We need to put together more information on the fuel debris and more experience on the salvage of the fuel debris to know if the plan can be completed as planned within the next 30 years,” he told the journalists.
The clean-up plan depends on how the molten fuel should be handled for long-term storage and management, he said.
The IAEA team’s review, the fifth since the disaster, was primarily conducted online due to the coronavirus pandemic. Only Xerri and another member of the team visited the plant this week before compiling and submitting a report to the Japanese government on Friday.
In the report, the team noted progress in a number of areas since its last review in 2018, including the removal of spent fuel from a storage pool in one of the damaged reactors, as well as a decision to start unloading massive amounts of processed fuel but still radioactive water stored at the plant into the ocean in 2023.
While there is now a better understanding of the molten fuel inside the reactors, details are still lacking and further research should be accelerated, according to the report. The team encouraged Japan to allocate sufficient resources to prepare for the measures beyond the next decade until the end of the decommissioning.
Research and development of new technologies needed for cleaning will take a decade or two, Xerri said, urging Japan to apply additional resources as soon as possible.
The report advised Japan to prepare comprehensive plans not only for the cleanup of the melted reactors, but also for the entire decommissioning, and a clearer picture of the end state.
“It’s important in any project to have targets, to have goals and to have a vision,” said Xerri.
Government officials and the plant operator, Tokyo Electric Power Company Holdings, did not provide a clear picture of what the plant would look like after the cleanup was completed.
In April, Japan announced that it would start dumping large amounts of treated but still radioactive water that has accumulated in the plant since the accident into the sea. TEPCO on Wednesday announced a plan to release water offshore via an underground tunnel after additional treatment to reduce radioactive material to allowable levels.
The IAEA has agreed to help facilitate the decommissioning and to cooperate in the monitoring and implementation of the drainage. A first IAEA water disposal mission is due to visit Japan in September.