Radiation spectroscopy of irradiated VVER-1200 fuel with burnable Am-absorber: A computational approach

Abstract

Safe storage of fresh and irradiated fuel is ensured by solving the problem of photon emission protection. The neutron component is usually not taken into account due to its low intensity. However, for the new VVER-1200 fuel, the neutron component consideration is a mandatory procedure for radiation safety. In this study, the radiation dose was calculated for a fuel consisting of UO₂ with a heterogeneous distribution of Am₂O₂ microcapsules, and the (α, n) component of the neutron background was evaluated. A comparative analysis of radiation characteristics of fuel assemblies shows that there is a significant excess in both the neutron and the photon components of the fuel under study. The yield and dose of neutrons from Am-containing fuel exceed those of uranium-based fuels by a factor of two, and when calculating the dose, it is necessary to take into account the energy spectrum of (α, n) neutrons in Am₂O₂ microcapsules. The analysis of the impact of Am on the photon component indicates that ensuring radiation safety for both fresh and irradiated fuels necessitates addressing challenges associated with photon radiation protection. This study aims to establish comprehensive procedures and guidelines for the handling of novel fuel materials during both production and post-irradiation processes within the reactor environment.

Keywords: (α; Americium; Burnable absorber; N) reaction; Particle emission spectra; Photon emission; VVER-1200.