Preliminary investigation into suitable techniques to measure the chemical yield of radionuclides in thermal neutron irradiated samples at AWE (Atomic Weapons Establishment)

Abstract

Radiochemical separation methods are required for the accurate measurement of radionuclides in complex matrices. To be able to quantify the results after the separation of radionuclides, known amounts of either radioactive tracers or inactive carrier solutions are added at the start of the separation. The added isotopes/elements are then measured at the end of the analysis to calculate the chemical yield for the element or isotope. The chemical yield data is applied to the counting data of the analytes of interest to produce quantified results. Recently, changes have been made to the techniques used to measure chemical yields at the Atomic Weapons Establishment for samples containing fission products. Preliminary development work using wavelength dispersive X-ray fluorescence and inductively coupled plasma–atomic emission spectrometry is discussed, including a comparison of results and evaluation of measurement uncertainty. The use of the techniques to measure fission products in a thermal neutron irradiated uranium sample is described.