Determination of 241Pu in nuclear waste slurries: A comparative study using LSC and ICP-MS

241Pu was determined in slurry samples from a nuclear reactor decommissioning project at the Paul Scherrer Institute (Switzerland). To validate the results, the 241Pu activities of five samples were determined by LSC (TriCarb and Quantulus) and ICP-MS, with each instrument at a different laboratory. In lack of certified reference materials for 241Pu, the methods were further validated using the 241Pu information values of two reference sediments (IAEA-300 and IAEA-384). Excellent agreement with the results was found between LSC and ICP-MS in the nuclear waste slurries and the reference sediments.

► Good agreement between the 241Pu activity of 5 slurry samples, using 3 measurement techniques.
► 241Pu information values of two IAEA samples agreed well for the 3 measurement techniques.
► Low detection limits were achieved; 1.8 Bq/kg (Quantulus), 2 Bq/kg (ICP-MS) and 3.5 Bq/kg (TriCarb).