Critical mass calculations performed on two plutonium metal/ionic liquid mi
xtures are presented and the results are compared with similar calculations
performed on aqueous systems. The ionic liquids considered are the 1-ethyl
-3-methyl imidazolium (EMI)/aluminum chloride (AlCl3) and the EMI/tetrafluo
roborate (BF4) systems. Our calculations indicate at least an order of magn
itude increase in the minimum critical concentration for the ionic liquid-p
lutonium mixtures over aqueous mixtures. The minimum critical concentration
s calculated for Pu/EMIC/AlCl3 and Pu/EMI/BF4 mixtures are 150 and 1000 g/l
, respectively. (C) 2001 Elsevier Science Ltd. All rights reserved.