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*; Aizawa, Naoto*; Kuriyama, Yasutoshi*; Uesugi, Tomonori*; Ishi, Yoshihiro*
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.