A robotic probe has found that radiation levels remain too high for humans to work inside one of the reactor buildings at the damaged Fukushima Daiichi nuclear power plant.
Tokyo Electric Power Company, the operator of the plant, plans to relocate 615 units of nuclear fuel from the spent fuel pool, which is located on the top floor of the No. 2 reactor building and is separate from the reactor itself.
TEPCO says the relocation will help reduce risks, including possible damage caused by earthquakes.
The No. 2 reactor underwent a meltdown, but did not experience a hydrogen explosion in the 2011 nuclear accident. The building is likely to still have a high concentration of radioactive materials.
Last month, TEPCO drilled a hole in the wall of the building in order to use a camera-equipped robot to create a detailed map of the radiation on the top floor.
On Monday, workers started the survey and measured radiation levels at 19 points, mainly near the opening. Up to 59 millisieverts were detected per hour.
That's above workers' allowable annual exposure of 50 millisieverts and more than half of their 5-year exposure limit. TEPCO has concluded it cannot let humans work inside the building.
TEPCO will use the results to determine specific ways to remove the fuel from the pool. It plans to start the work in fiscal 2023.