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Tandem inductively coupled plasma mass spectrometry (ICP-MS/MS) has demonstrated effective online removal of interferences for a number of medium and long-lived radionuclides including 90Sr, 129I, 135/137Cs and 237Np. This reduces or removes the dependence on relatively time consuming offline chemical separation, improving sample throughput and offering economic benefits for end users through reduced procedural time, analyst time, secondary waste arisings and quantity of resins and reagents required. This work demonstrates the development and application of a method for measuring multiple radionuclides (including 63Ni, 90Sr, 93Zr, 99Tc, 129I, 237Np, 239Pu) and stable elements in various sample matrices in a single measurement. Separate instrument modes customised for individual radionuclides were combined into a single run, each using a different instrument setup depending on the extent of interference removal required. The measurement time was approximately seven minutes and consumed 3.5 mL for each sample. Instrument conditions were optimised for each radionuclide using stable and radioactive standards, and then validated using samples including aqueous wastes from a nuclear site, air filters following microwave dissolution, groundwater, and soil, sediment and concrete samples following borate fusion dissolution. Matrix-matched calibration standards were prepared, and a multi-element standard solution was used as an internal standard. The limits of detection were compared to regulatory limits, which showed that longer-lived radionuclides such as 93Zr, 99Tc, 129I and 237Np can be directly measured, whilst shorter-lived radionuclides such as 90Sr and 63Ni require separation and pre-concentration prior to sample introduction. The method provides a significant amount of information on stable and radioactive composition in a single measurement, with the potential to further expand the number of radionuclides measurable as part of this single procedure. [ABSTRACT FROM AUTHOR]

Decommissioning and monitoring around nuclear sites presents challenges with regards to the range of sample matrices and radionuclides that must be accurately characterised. Over the last few decades, inductively coupled plasma mass spectrometry (ICP-MS) has been increasingly used in the nuclear sector as a rapid alternative to decay counting techniques for long-lived radionuclides, as well as an expanding range of shorter-lived radionuclides. The presence of various interferences still presents a major challenge in achieving accurate measurements, often necessitating extensive chemical clean-up prior to measurement. This study evaluates the potential application of tandem ICP-MS/MS for the measurement of a range of radionuclides of interest to nuclear decommissioning and waste management. The flexibility of the instrumental setup is shown in achieving improved interference removal compared to alternative instrument designs, improving sample throughput by reducing reliance on offline separation, and increasing the potential application of ICP-MS/MS for routine measurement of difficult-to-measure radionuclides. [ABSTRACT FROM AUTHOR]