The determination of hydrogen and deuterium in Zr–2.5Nb material by hot vacuum extraction mass spectrometry

An analysis method for the determination of H and D concentrations in Zr–2.5Nb material has been established based on hot vacuum extraction and isotope dilution mass spectrometry. Hot vacuum extraction enables complete removal of the hydrogen isotopes from the sample. The isotope dilution technique is used to determine quantitatively the amount of hydrogen isotopes in the extracted gas. Methods for preparing standards of H, D or H and D in Zr–2.5Nb have also been established. These ‘in-house’ standards are used to assess the performance of the analysis method. The analysis uncertainty, based on the determined content relative to the dosed H or D isotope content of each standard, is 1% (at a level of confidence of 95%) for samples containing greater than ∼5 μmoles H or D. The uncertainty increases to 5% as the sample content decreases to 0.5 μmoles H or D. The uncertainty of this analysis method is well within the requirements for surveillance examinations of CANDU® reactors and post-irradiation examinations of reactor components.