Problems of sample preparation can be avoided by analyzing the solids as slurries. A sealed sample cell with a belt-driven stirrer was constructed for use with the GE XRD-3 spectrometer. A problem arose owing to radiolytic gas; an open, bottom-window cell would solve the problem. A ThO/sub 2/ analysis was carried out; the ThO/sub 2/ assay was observed to increase with prolonged x-ray exposure. (DLC)