Development of stable solidification technique of ALPS sediment wastes by apatite ceramics (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*

JAEA-Review 2022-076, 227 Pages, 2023/03

JAEA-Review-2022-076.pdf:9.42MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station (1F), Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Development of stable solidification technique of ALPS sediment wastes by apatite ceramics" conducted from FY2019 to FY2021. Since the final year of this proposal was FY2021, the results for three fiscal years were summarized. The present study aims to establish an apatite solidification process of radioactive sediment wastes, which were generated from the ALPS process manipulating the large amount of contaminated water from 1F. We selected the precipitation method and post stabilization for engineering-scale process. Investigation on composition, structure and elution properties of apatite and related phosphate waste forms fabricated from the simulated ALPS sediment wastes were implemented.

Power-balance control by Slug Tuner for the 175MHz Radio-Frequency quadrupole (RFQ) linac in IFMIF project

Maebara, Sunao; Moriyama, Shinichi; Saigusa, Mikio*; Sugimoto, Masayoshi; Imai, Tsuyoshi*; Takeuchi, Hiroshi

Fusion Science and Technology, 47(4), p.941 - 945, 2005/05

https://doi.org/10.13182/FST05-A810

For tuning the 175MHz RFQ used in the baseline design of IFMIF, the RF power-balance control by slug tuner is indispensable because the RF power-balance for quadrupole operation mode (TE) in each RFQ quadrant will be affected by the insertion of the loop antennas and pick-up coils. In this study, RF power-balance recovery by slug tuners have been measured by using a low power module of 175MHz RFQ mock-up. The optimal insertion depth of loop antenna was determined to be 3 cm for realizing the appropriate phase differences of TE mode. Under this condition, cylindrical slug tuners were inserted, and S parameters in each cavity were measured. As a typical result, RF power-balance control less than 20% error can be achieved in case of 3cm tuner up to 3cm insertion.