First nuclear transmutation of Np and Am by accelerator-driven system at Kyoto University Critical Assembly

Pyeon, C. H.*; Yamanaka, Masao*; Oizumi, Akito; Fukushima, Masahiro; Chiba, Go*; Watanabe, Kenichi*; Endo, Tomohiro*; Van Rooijen, W. G.*; Hashimoto, Kengo*; Sakon, Atsushi*; et al.

Journal of Nuclear Science and Technology, 56(8), p.684 - 689, 2019/08

https://doi.org/10.1080/00223131.2019.1618406

This study demonstrates, for the first time, the principle of nuclear transmutation of minor actinide (MA) by the accelerator-driven system (ADS) through the injection of high-energy neutrons into the subcritical core at the Kyoto University Critical Assembly. The main objective of the experiments is to confirm fission reactions of neptunium-237 (Np) and americium-241 (Am), and capture reactions of Np. Subcritical irradiation of Np and Am foils is conducted in a hard spectrum core with the use of the back-to-back fission chamber that obtains simultaneously two signals from specially installed test (Np or Am) and reference (uranium-235) foils. The first nuclear transmutation of Np and Am by ADS soundly implemented by combining the subcritical core and the 100 MeV proton accelerator, and the use of a lead-bismuth target, is conclusively demonstrated through the experimental results of fission and capture reaction events.

Evaluation Report of the Melt Refining Decontamination Technology

Miyamoto, Yasuaki; Yamanaka, Tomohiro*; Aoyama, Makoto; Takahashi, Kuniaki; Suto, Osamu

JNC TN8400 2003-044, 127 Pages, 2003/03

JNC-TN8400-2003-044.pdf:19.07MB

It examined for the uranium system metal wastes which can be expected a high decontamination performance by applying melt refining decontamination technology, and the decontamination performance by using a refractories melting furnace and a cold crucible induction melting furnace was confirmed. Moreover, evaluation about technical applicability, such as engineering characteristics by the examination using an engineering scale melting furnace, was carried out.