Data on plutonium sorption onto rock; Results of the experiment for data on plutonium sorption onto tuff under conditions of reducing and of presence of nitrate

Suguro, Toshiyasu; Nishikawa, Yoshiaki*; Komuro, Takashi*; Kagawa, Akio ; Kashiwazaki, Hiroshi ; Yamada, Kazuo

For safety assessment of TRU waste disposal, data on sorption data of plutonium on Tuff have been obtained by a static batch-type experiment. Because the repository condition will be reducing and be affected by considerable amount of nitrate in waste, the authors carried out the experiments using Tuff under the reducing (NaSO as added as reductant) and anoxic condition (O1 ppm) and solution of 0 to 0.5 M NaNO. The experimental results suggest that distribution coefficient (Kd) ranges 0.2 to 0.7 m kg in case of L/S=0.1 m kg. Similarly the Kd ranges, 1 to 7 m kg at L/S=1 m kg. However, almost samples of the solution after experiments were plutonium solubility less than detection limit(10mol/dm) of alpha spectrometer. The reason, it is guessed plutonium coprecipitation with calcium hydroxide, because experiments using saturated calcium hydroxide in the liquid.