Precipitation of actinides as fluorides or hydroxides for high-resolution alpha spectrometry

Management of radioactive wastes requires sensitive, accurate and reliable analytical procedures by which the radionuclides of interest can be determined in a wide variety of sample types. Procedure are given for precipitating and mounting all actinides from thorium through californium for high-resolution alpha spectrometry by two mutually complimentary systems. One system involves precipitation of fluorides from dilute acid in which most actinides can be separated from each other and from many common interferences by proper use of oxidizing and reducing agents. Elements forming strong fluoride complexes such as iron, titanium, zirconium, etc. , do not interfere, but calcium interferes seriously. The other system involves precipitation of hydroxides from strongly alkaline solutions of ethylenediaminetetraacetic acid in which large quantities of calcium can be tolerated. More importantly, the latter system can be used to recover actinides coprecipitated with barium sulfate, which in turn permits use of potassium fluoride fusion to guarantee complete dissolution of the most refractory types of samples.