Determination of thorium in plutonium by X-ray spectrometry

An X-ray fluorescence method for the determination of thorium (0.1 to 1.2 %) in plutonium-238 was developed. The PuO₂ is mounted in a dimpled slide, and the slide is packaged so that the plutonium and thorium L-alpha lines can be counted in a nonradioactive laboratory. A standard deviation of 0.02 % is estimated. The method is applicable to both solid and solution samples.