27 Novembre 2015
November 27, 2015
By HIROMI KUMAI/ Staff Writer
Tokyo Electric Power Co. plans to remove the top part of the No. 2 reactor building at the Fukushima No. 1 nuclear plant by fiscal 2018 to empty a nuclear fuel storage pool inside.
Dismantling work will start next summer at the earliest, the utility said Nov. 26.
The No. 1, No. 2 and No. 3 reactors at the plant melted down after the Great East Japan Earthquake and tsunami struck in March 2011. Hydrogen explosions destroyed the No. 1 and No. 3 reactor buildings, but the No. 2 reactor building remained relatively intact.
The utility said it will come up with a plan in two years on how to remove the 615 nuclear fuel assemblies in the storage pool located in the upper portion of the building. It intends to start removing the fuel assemblies in fiscal 2020.
One tricky part of the dismantling work will be ensuring that radioactive materials do not escape from the building. Airborne radiation levels above the building in 2013 exceeded 800 millisieverts per hour at some locations.
TEPCO plans to spray synthetic resins and take other measures to contain radioactive dust during the dismantling process. It is also considering installing a cover over the building to prevent radioactive materials from spreading when it tears down the building walls using heavy machinery.
TEPCO had considered removing only part of the uppermost portion of the building to contain the large amount of radioactive materials inside. But the company decided to dismantle the entire top-level portion to make it easier to remove contaminated debris and nuclear fuel.