Uranium content in phosphate fertilizers commercially produced in Brazil

This work presents the results of the determination of uranium concentration in the most commonly used phosphate fertilizers employed in Brazilian agricultural land. The technique employed was the nuclear fission track registration in plastic foils of Makrofol KG (dry method), together with a discharge chamber system for track counting. Phosphate fertilizer samples and uranium standards were irradiated together with thermal neutrons in the 2 MW IEA-R1 research reactor of IPEN/SP. The uranium concentration in Brazilian phosphate fertilizers ranging from 5.17 to 54.3 ppm is in good agreement with the results reported in the literature for similar fertilizers produced in other countries.