Numerical Neutron Emission Spectrometry and Radiation of VVER-1200 Reactor Fuel

Uranium-gadolinium fuel in a homogeneous design with axial profiling of fuel elements has received practical application. The possibility of heterogeneous use of Gd2O3, ZrB2, Am2O3, and other burnable and alloying additives is being investigated. Such additives make it possible to maintain the thermal conductivity of the fuel at the level of conventional oxide fuel. The modifications under study show satisfactory behavior under irradiation at extremely high temperatures and burnup. However, the issues of radiation safety when handling both fresh and spent fuel remain less studied. In this work, a computational assessment of the neutron component of the radiation characteristics of a UO2 composition with a heterogeneous variant of localization of natGd2O3 and Am2O3 microcapsules has been carried out. This design option does not impair the thermal conductivity of the fuel and has positive effect on the nuclear physical and thermophysical properties of the fuel. Americium has been studied not only as a possible alternative to Gd but also from the perspective of its possible utilization in thermal reactors. The influence of Am on the photon component of radiation characteristics of fresh fuel has been considered. It is concluded that the radiation safety of fresh and irradiated products containing Am should be achieved primarily by solving problems of protection from photon radiation. The research has been carried out to develop procedures and regulations for handling new fuel during its manufacture and after irradiation in reactor. The studies have been carried out using verified calculation codes of the MCNP 6.2 and Nedis 2m programs.