Choice of protective barriers for radioactive wastes' localization

In this paper a protective ability of engineering barriers based on possibility estimation of radionuclides delocalization from storage is discussed. Radionuclide migration through the thickness of protective barriers (multi-layer medium) is described with known one-degree equation of non-stationary diffusive-convective mass-transfer. Equation has put in computer program used for modeling of mass-transfer processes in protective layers of designed storage facilities intended for low- and middle-radioactive wastes. Protective layers' parameters as well as theirs composed material and their thickness has been selected during modeling process under corresponding diffusion coefficient, sorption coefficient and convention rate. Here with two variants of radionuclides delocalization into surrounding have been examined: 1) the best variant - radionuclides diffusion with maximum activity through protective barriers (protective barriers are not broken); 2) the worst variant -radionuclides'diffusion through protective barriers with regard of convective transfer (protective barriers are broken). The main criterion of protective barriers' choice is attainment of dominating radionuclides concentration not increasing the established norms, on the side of protective layer contacting to surroundings during radioactive wastes storage-time. Dominating radionuclides have been chosen either as radionuclides with high migration ability and/or as these with maximum content in wastes. 4 figs