Separation of plutonium species

Some results of plutonium oxidation-state analysis carried out on samples of Lake Trawsfynydd water which had been passed through different sizes of hollow-fibre cartridge are shown in Fig. 13.7 where it can be seen that over 90% of the plutonium which passed through the 3 k molecular weight nominal cut-off 

Nominal pore size/molecule weight (Nanometers/Daltons) 

In a review of available data relating to the physico-chemical speciation of plutonium in the Irish Sea and western Mediterranean, Mitchell et ai. (1995) concluded that a high percentage of the plutonium is present as Puv and not retained by a 1 kD filter, thus demonstrating that plutonium in the oxidised state is in true solution. The data also indicate that a significant proportion of plutonium in the reduced state is associated with colloids and that the size of the colloidal particles or aggregates involved ( 10kD) is considerably smaller than those observed in non-saline waters. 

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