137Cs Sorption on the Loams of the Republic of Belarus

It was established that the content of the main clay minerals in the loam sample from the Fanipolskoye deposit is 13.6 wt % for montmorillonite and 3.3 wt % for illite. It was determined that the pH of solution in the range of 4–12 has virtually no effect on ¹³⁷Cs⁺ sorption by the loam. The distribution coefficient (K_d) of ¹³⁷Cs for the specified loam sample with a K⁺ concentration in the solution of up to 0.01 mol/dm³ is higher than 10³ dm³/kg, which indicates that the ¹³⁷Cs sorption is efficient. The loam contains two types of sorption sites, T₁ and T₂, with different selectivity and capacity toward Cs⁺. The sorption capacities of sites T₁ and T₂ for Cs are 4.0 × 10^–5 and 1.2 × 10^–2 mol/kg, respectively, and the values of K_d of Cs for these sites differ by a factor of 20 and are 1.6 × 10⁴ and 7.9 × 10² dm³/kg. The loam from the Fanipolskoye deposit is shown to be suitable as a buffer backfill for the disposal site of very low-level radioactive waste from the Belarusian NPP.