Modeling the release and transport of ~(90)Sr radionuclides from a superficial nuclear storage facility

摘要

This work illustrates an integrated model for (i) predicting the evolution of radionuclide concentrations due to releases from a spent fuel storage pool and (ii) providing a preliminary assessment of the radiological risk for the local population. The model integrates (i) a particle tracking algorithm for radionuclide transport based on the Kolmogorov-Dmitriev theory of branching stochastic processes and (ii) a semi-empirical model for representing the effects of seasonal variations in the water table level on the radionuclide concentrations. A real case study is considered concerning the release of Sr-90 from the spent fuel storage pool at the EUREX site in Italy. The integrated model is calibrated by a genetic algorithm optimization based on observation data of water table levels and Sr-90 concentrations available from the local monitoring network. The proposed model offers a satisfactory trade-off between a detailed physical and geometrical description of the transport processes and computational efficiency.