The government hopes to decide around September on a method for extracting fuel debris from reactor 3 at the Fukushima No. 1 nuclear complex based on findings from a recent robot inspection, industry minister Hiroshige Seko said Tuesday.
“Valuable information has been obtained from the survey inside the reactor using a submersible robot,” Seko said, referring to a specially made device.
During last week’s probe, the robot captured images of what engineers believe is “highly likely” to be melted fuel debris scattered around the crippled reactor. It was the first such discovery at the plant.
The government and the operator of the facility, Tokyo Electric Power Company Holdings Inc., aim to scrap reactors 1, 2 and 3 at the Fukushima No. 1 complex. The three reactors suffered core meltdowns following the massive earthquake and tsunami in 2011 that triggered the world’s worst nuclear disaster since the 1986 Chernobyl crisis.
Under a road map for decommissioning, they hope to finalize a debris extraction method by the first half of fiscal 2018 and start work in 2021.
Removing the fuel debris is one of the most difficult parts of the decommissioning project, which is expected to take at least 30 to 40 years. Critics question whether plans will stay on schedule, as radiation levels in the reactors remain extremely high.
“At the current stage, we will proceed with the decommissioning in line with the road map,” Seko said, noting the need to evaluate the feasibility of the operation at the same time.
Images taken by the robot showed what is likely melted fuel attached to control rod devices extending to the bottom of the reactor’s pressure vessel.
A build-up of deposits on the bottom of the primary containment vessel was also found up to a height of at least 1 meter, according to the operator.