Tokyo Electric Power Co. on Aug. 2 removed a 20-ton piece of debris from a nuclear fuel storage pool, a small but critical step in decommissioning the crippled Fukushima No. 1 nuclear power plant.
Tokyo Electric Power Co. on Aug. 2 removed a 20-ton piece of debris from a nuclear fuel storage pool, a small but critical step in decommissioning the crippled Fukushima No. 1 nuclear power plant.
It was the largest piece of debris left in the No. 3 reactor building’s storage pool, which is holding 566 nuclear fuel assemblies.
The reactor building was heavily damaged by a hydrogen explosion shortly after the Great East Japan Earthquake and tsunami on March 11, 2011, triggered the nuclear crisis at the plant.
The object removed was part of fuel replacement equipment used to load and unload nuclear fuel at the No. 3 reactor. It has prevented TEPCO from removing the nuclear fuel assemblies in the pool to a safer location.
The piece of equipment originally weighed 35 tons, but TEPCO used an underwater cutting device to pare it down to 20 tons.
The utility began lifting the debris shortly before noon. Workers remotely controlled two large cranes, equipped with three specially designed hooks, to pull out the debris while closely monitoring the process with cameras.
The delicate operation required the utmost attention to detail to prevent the debris from touching the pool’s walls. If it had dropped back into the pool, it could have damaged the nuclear fuel assemblies.
The debris was safely placed on the ground after 90 minutes, during which time TEPCO suspended all outdoor decommissioning work at the plant compound in case of an accident.
After removing the smaller debris from the pool, the utility plans to install special equipment on the upper structure of the reactor building to lift out the nuclear fuel assemblies.
TEPCO plans to start the fuel-removal operation in January 2018 at the earliest.