Analytical determination of alpha emitters in waste samples containing a larger number of radionuclides

For the disposal of wastes containing alpha emitting nuclides it is necessary to determine the activity of about 20 nuclides of the elements thorium, protactinium, neptunium, uranium, plutonium, americium and curium. In general, the activity of alpha emitting nuclides is determined by the measurement of samples to be prepared such that the emission of alpha particles takes place largely without loss of energy. However, the separation of the nuclides from sample matrix, purification and preparation of the samples is always connected with losses. Therefore, tracers like U-232, Pu-236, Pu-242, Am-243, etc. which normally are not expected to be present in the sample have to be added in order to determine the yield. Because of the requirement to determine these isotopes which are used as tracers for yield determination and the determination of very low concentrations in the presence of much higher concentration of other nuclides it was necessary to develop a new analytical procedure. (author)