RADIOLOGICAL CONSEQUENCES OF AMENDING SOILS WITH BAUXITE RESIDUE GYPSUM MIXTURES

This paper reports on the gamma (gamma) radiation flux from sandy soil s of the Swan Coastal Plain treated with bauxite residue/gypsum at var ious application rates and assesses the radiological significance of s oil amendment in relation to currently accepted standards. Amendment r ates of up to 2000 t ha-1 of bauxite residue were used. There is a lin ear increase of incremental gamma dose with increasing rate of residue . The 1 mSv limit for incremental gamma dose exposure for the general public is reached for 100% occupancy at an amendment rate of 1500 t ha -1 of bauxite residue. The gamma rate of approximately 0.15 muGy h-1 i s similar to that for soils of much of the area between Bunbury and Ca pel in the south-west of Western Australia and is significantly lower than levels for Minninup beach where there are deposits of mineral san ds.