Numerical tools for the evaluation of super-compacted radioactive waste residues

Numerical modeling and simulations of radioactive emissions from nuclear waste residues are important for the assessment of the long-term hazard potential and safety properties. The specific radioactive waste residues considered in this paper are dried and super-compacted metallic remains after sheering and dissolving spent nuclear fuel elements from commercial NPP's in the process of fuel reprocessing. They consist mainly of hulls and end pieces of the fuel assemblies and some additional technological metallic waste from the reprocessing itself. Because of activation and some small percentage of spent fuel material adhering to hulls, these rad-waste residues are classified as medium active waste. The goal of this work is to develop numerical tools to evaluate the final repository relevant properties of rad-waste residues. Simulating the gamma- and neutron-emission spectra allows numerical studying the effect of varying the concentration, activity and geometrical position of key nuclides in a heterogeneous material embedding. (author)