Mockup Experiments on the Thorium-Loaded Accelerator-Driven System at the Kyoto University Critical Assembly

Accelerator-Driven System (ADS) Study in Kyoto University Research Reactor Institute (KURRI)

“…Thus, an expected physical effect was indeed observed as a result of the neutron spectrum change obtained by varying the moderator materials in the fuel assembly. Additionally, the accuracy [5] of experimental and numerical analyses was compared successfully with the ratio (C/E) of calculations and experiments around the relative difference of 10 %, through the subcritical parameter of neutron multiplication M.…”

“…In the Th-HEU-PE core, the prompt neutron decay constant (Table 9.1) at 3 He detector #1 was different from those at the others by the least-squares fitting, regardless of the kind of external neutron source and the position of neutron detection. It was considered overestimated, especially at detector #1, which was located near the external In(n, γ) 116m In reaction rates obtained from the thorium-loaded ADS experiments with 100 MeV protons [5] neutron source. The two different neutron sources provided different delayed neutron backgrounds.…”

“…At the Kyoto University Critical Assembly (KUCA), a series of ADS experiments [1][2][3][4][5] was carried out by coupling with the fixed-field alternating gradient (FFAG) accelerator [6][7][8], and the spallation neutrons generated by 100 MeV protons from the FFAG accelerator were successfully injected into uranium- [1,2,4] and thorium-loaded [5,7] cores.…”

“…The mockup experiments [5] of thorium-loaded ADS carried out by varying the neutron spectrum and the external neutron source were aimed at investigating the influence of different neutron profiles on thorium capture reactions and the prompt and delayed neutron behaviors in the subcritical system. The results provided important effects of the neutron spectrum and the external neutron source on both static and kinetic parameters: the effect of the neutron spectrum was investigated by varying the moderator material in the fuel region, and that of external neutron source by injecting separately 14 MeV neutrons and 100 MeV protons into the thorium-loaded core varying the moderator.…”

Experimental Study on Accelerator-Driven System at Kyoto University Critical Assembly

“…The experimental study [1]- [8] on the accelerator-driven system (ADS) is being conducted for a next-generation neutron source and an application of nuclear transmutation with the combined use of the Kyoto University Critical Assembly (KUCA; A-core: solid-moderated and -reflected core) and the accelerator: the fixed-field alternating gradient (FFAG) accelerator, in the Kyoto University Research Reactor Institute. The spallation neutrons generated by 100 MeV protons from the FFAG accelerator had been successfully injected into the uranium-loaded core [1], and also into the thorium-loaded core [2].…”