Development and comparison of high accuracy thermal ionization mass spectrometry methods for uranium isotope ratios determination in nuclear fuel

This study presents the development and the comparison of high accuracy methods for uranium isotope determination by thermal ionization mass spectrometry. Two methods for uranium minor isotope ratio determination were compared in term of accuracy, analysable quantity, analysis time and versatility: the total evaporation and the classical method with multi-dynamic sequences. The mathematical correction of the abundance sensitivity and the detector calibration within the classical method helps decreasing the uncertainties and the biases compared to the total evaporation method. This comparative study was conducted within the framework of the '2017 Nuclear Material Round Robin' participation organized by the International Atomic Energy Agency. (authors)