As of March, the volume of treated water in storage tanks at the NPPs had reached approximately 1,050,000 cubic meters (concentration level: 0.02 micro gram per litter). TEPCO’s current plans include the construction of additional tanks for total storage of up 1,370,000 cubic meters, but the available land suitable for the tanks is reaching a limit. Moreover, working areas need to be ensured for the removal of fuel debris, as well as plots for the construction of storage facilities for spent fuel assemblies (numbering about ten thousand), among other things, before decommissioning can proceed, thereby reducing the risk for the whole facility.
A task force of experts, also under ANRE, evaluated 5 methods of dealing with the tritium water from the viewpoints of regulatory and technological feasibility, as follows: geosphere injection, offshore release, vapor release, hydrogen release, and underground burial.
The experts found that regulatory standards already exist, along with domestic and overseas experience, for the 2 methods of offshore release and vapor release. Meanwhile, there are no applicable standards for the geosphere injection method, nor has any long-term monitoring method been established for it. On the other hand, R&D on pre-treatment and scaling-up would be needed for hydrogen release to be used, while future monitoring would have to be considered before underground burial could be utilized, along with new regulatory standards.
At the July 13 meeting, members of the ANRE subcommittee discussed draft materials explaining the societal effects of unfounded fears and rumors, along with various technical aspects. Those materials are to be used at the explanatory meetings and public hearings to be held in Tomioka Town on August 30 and Koriyama City on August 31, both in Fukushima Prefecture, and in Tokyo on August 31. Opinions heard from a wide range of people at those events will then be reflected in future deliberations.
