Accurate determination of uranium and thorium in Egyptian oil ashes

Uranium and thorium have been measured in oil ash samples collected from four Egyptian power plants that use heavy fuel oil. The U and Th content in oil ashes was determined by INAA, ICP-MS, ICP-OES, WDXRF, and EDXRF without any sample pretreatment. Samples were digested using two acid, four acid, or fusion method. The concentration of U and Th were found to be within the average worldwide value. Uranium and thorium content in heavy fuel oil were also measured for the first time. For quality control of the analytical data, three internal reference materials were prepared and used.