DILUENT PARAFFIN NATURE AND PLUTONIUM(IV) ORGANIC SOLUTION LAMINATION- NEW RESULTS AND NEW APPROACH

The knowledge of the relation between the diluent composition and stru cture and the critical (maximum achievable) concentration (CC(Me)) of metals, including plutonium(IV), in the organic phase is an actual goa l of a radiochemical extraction technology (PUREX process). Using gamm a-spectrometry analysis with high accuracy, the parameter CC(Pu) has b een determined in application to Pu(IV) nitrate solution in 30% (vol.) TBP diluent solutions. n-Paraffins C10C16, iso-paraffins (mono- and d imethylderivatives), iso-paraffins with C-quaternare atoms (hydrogenat ed mixtures of tetra- and pentapropylene isomers) have been used as di luents. Regular correlations between CC(Pu) parameters and some indivi dual (and mixture) diluent structure characteristics, including practi cally linear inversely proportional decrease of CC(Pu) with C-atom num ber increase (in molecules of n-CnH2n+2), symbatically development of this relation to both the paraffin types (n- and iso-) have been found . The general straight proportional relation between CC(Pu)-parameter and fluidity (F=1/eta, where eta-dynamic viscosity at given temperatur e) has been discovered for all paraffins investigated - both individua l and mixtures - at different temperatures.