Data on Plutonium Sorption onto Cementitious Materials under Conditions of Reducing and of Presence of Nitrate

Toshiyasu, Suguro,; Notoya, Shin ; Nishikawa, Yoshiaki*; Nakamura, Ryosuke*; Shibutani, Tomoki; Kuroha, Mitsuhiko; Kamei, Gento 

In terms of safety assessment of TRU waste disposal, data on plutonium sorption on cementitious materials have been obtained by means of a static batch-type experiment. Because the repository condition will be reducing and be affected by considerable amount of nitrate, the authors carried out the experiments using ordinary portland cement (OPC) under the reducing (NaSO as added as reductant) and anoxic condition (O 1ppm) and solution of 0 to 0.5 M NaNO. Other experimental conditions are : liquid/solid (L/S) ratios ; 100 and 1000 mL g, Initially aaded plutonium; 2.8410M, Temperature; 255C and Reaction times; 7, 14 and 28 days. The experimental results suggest that distribution coefficient () ranges 50 to 1000 mL g in case of L/S=100mL g. Similarly the ranges, 100 to 10000 mL g at L/S=1000mL g. These values tend to increase with lapsing reaction time. On the basis of these results, we recommend 50mL g as a conservative value of plutonium on OPC in a TRU waste repository condition.