Evaluation of Minor Actinides Build-up in VVER Power Reactors’ Fuel Assemblies

The recent developments in the electricity production policies suggest major increase in the share of the nuclear power in the following decades. This trend will pull the nuclear spent fuel storage and handling from the current populist rhetoric to a real political and engineering task to be solved. One of the main challenges is the minor actinides build-up in the fuel during its use in the reactor core. These, together with the plutonium build-up are the main sources of residual heating and radiotoxicity of the spent nuclear fuel. Therefore a long-term solution for their further utilization should be found. The good knowledge of the isotopes content in the spent fuel is vital for investigation of the further handling possibilities. Three fuel assemblies for reactors of VVER type are studied in this paper by means of theoretical modelling. Modern codes and contemporary crossections are used for the calculations. Results for regular and extended fuel cycles are obtained for the minor actinides build-up during their operation. The obtained results provide sound basis for discussion on the further approaches for spent fuel utilization.