According to TEPCO’s storage management plan, secondary wastes from water treatment stored in adsorption towers that contain large amounts of radioactivity will be prioritized for storage in the building.

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, stabilization (dehydration) treatment 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 Laboratory-1, 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, absorbent of cesium adsorbent tower (KURION and SARRY) collected at the Fukushima Daiichi NPS site has been transported to JAEA's Ibaraki analysis facility, 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.

From the perspective of treatment, the low-temperature treatment technology is undergoing full-scale testing to confirm the prospects for application in actual facilities as well as the clarification of rapid curing mechanism occurred during full-scale testing of ALPS carbonate slurry with low-temperature treatment technology, meanwhile, further investigation of solidification feasibility testing methods and evaluation methods for the stability (leaching characteristics, long-term alteration phenomena, radiation effects, etc.) of solidified products produced by various treatment technologies are also being studied. In addition, in order to expand the range of application and other technology options, 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.

For disposal, the critical 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 critical scenarios and other information. In addition, the development of disposal concept options is being carried out as a countermeasure to these needs, and the technology for the development of disposal concept options is being advanced.

As the PCV internal investigation at the Unit-1, in addition to the information on the basement floor obtained by the underwater ROV survey by FY2023, the information on the condition of the existing structure outside and inside the pedestal, and visual images related to deposits, fallen objects, etc. was obtained from the PCV internal investigation(airborne survey) which was conducted from February to March 2024, mainly in the first floor area.