A fuel for generation IV nuclear energy system: Isotopic composition and radiation characteristics

This paper reports on an important issue of designing appropriate nuclear fuel of a high-temperature gas-cooled nuclear reactor operating in a thorium-plutonium nuclear fuel cycle. The neutronic calculations for a fuel of specific isotopic composition were performed before the analyses were done on the alpha emission probabilities, and on the neutron and photon sources as a result of (α,n) reaction. The main focus was on the quantitative evaluation of the neutron yield and the neutron energy spectrum for the generated neutrons through (α,n) reaction on light nuclei of dispersed nuclear fuel. Tests were carried out with the aim of creating an efficient calculation tool for the initial evaluation of the radiation characteristics for the irradiated multilayer nuclear fuel with different configurations and compositions. •Neutronic properties of compound isotope (Th,Pu)O2 as a nuclear fuel were studied.•Neutron yield and energy spectrum of (Th,Pu)O2 through (α,n) reaction were estimated.•Analytical calculation method was proposed to characterize the multi-layered spent fuel, (Th,Pu)O2.