Solid state reaction of ammonium sulphate with plutonium oxide in calcium fluoride matrix

The chemistry of plutonium is important for assessing potential behaviour of radioactive waste under conditions of geologic disposal. Reactions of plutonium oxide and plutonium fluoride in calcium fluoride matrix mixed with (NH4)2SO4 was monitored by TG-DTA and XRD analysis. Products formed at different temperatures were characterised by X-ray diffraction method. Thermal and X-ray diffraction study showed the formation of (NH4)2Pu (SO4)3 at 325 deg C, Pu(SO4)2 at 450 deg C and PuO2 at 650 deg C. More than 95% of plutonium content in the mixture was recovered by employing thermal decomposition method. (author)