Physicochemical characterisation of depleted uranium (DU) particles at a UK firing test range

Depleted uranium (DU) particles were isolated from soils at Eskmeals, UK, where DU munitions have been tested against hard targets and unfired DU buried in soils for corrosion studies. Using electron microscopy and X-ray analyses, three classes of particles were identified: (1) DU aerosols and fragments, typically 1-20 μm diameter, composed mainly of uranium as UO₂ and U₃O₈, (2) solidified molten particles, typically 200-500 μm diameter, composed of U, mixed with Fe from target materials and (3) deposits and coatings, often of metaschoepite on sand grains up to 500 μm diameter. The first two particle types are derived from firing impacts, the last from corrosion of buried uranium metal. Alpha and mass spectrometry allowed quantitative elemental and isotopic characterisation of DU-containing particulate environmental samples.