TEPCO's storage management plan calls for the storage of secondary water treatment waste in the building, with priority given to the adsorption tower that contains large amounts of radioactive waste.

For the secondary waste generated from contaminated water treatment, a large waste storage facility is under construction as a storage facility for adsorption towers and the like. In addition, implementation of stabilization (dehydration) process of the ALPS slurry generated from the multi-nuclide removal system, etc., which has high water content rate and is fluid, will be investigated, and the sludge from the decontamination system will be transferred to a storing facility on higher ground (collection to be started in FY2027).

Considering the radiation effects of the slurry, the transfer of slurry from the HIC, whose integrity cannot be confirmed in the event of a fall, is being conducted with the aim of completing the transfer before the start of operation of the slurry stabilization treatment facility.

At the Radioactive Material Analysis and Research Facility Laboratory1, a demonstration to use analytical methods to obtain data easily and quickly as a standard analytical method was completed in FY2023, with full-scale operations beginning in FY2024.

In order to obtain analytical data on high-dose waste, adsorbent material from cesium adsorption vessel (KURION and SARRY) collected at the Fukushima Daiichi Nuclear Power Plant site was transported to the analysis facility at the JAEA Ibaraki site, and analytical methods are being investigated.

As a countermeasure against hydrogen generation during storage of high-dose waste, factors(hydrogen embrittlement, radiation degradation, etc.) affecting filter degradation (blockage, damage, etc.) and methods to confirm these factors have been investigated.

In terms of treatment, the feasibility of applying low-temperature treatment technology to actual equipment has been confirmed through full-scale tests. In addition, methods for testing solidification feasibility and evaluating the stability (leaching characteristics, long-term alteration phenomena, radiation effects, etc.) of solidified products produced by various treatment technologies are being studied. In addition, in order to contribute to expansion of the technology options such as the expansion of the scope of application, for pyrolysis treatment, which is being investigated as a candidate for intermediate treatment technology, basic tests of pyrolysis have confirmed wastes with a large weight reduction rate that can be mineralized, full-scale tests have confirmed its applicability, and efforts are being made to stabilize the generated treatment residues.

Regarding disposal, the key scenarios that could have a significant impact on the feasibility of radioactive waste disposal are being identified, and the needs for disposal concepts are being identified based on the key scenarios and other information. In addition, the establishment of disposal concept options is being carried out as a measure to respond to these needs, and the technology for the establishment of disposal concept options is being advanced.

In addition to the information on the basement floor obtained by the underwater ROV survey by FY2023 as part of the PCV internal investigation at the Unit 1, an PCV internal investigation (a section in the air) was conducted from February to March 2024, mainly in the first floor area, resulting in obtaining information on the condition of the existing structure outside and inside the pedestal, and video images related to deposits, fallen objects, etc.