Development of elemental and isotope analysis for nuclear safeguards in CIAE

The 1990s saw significant non-proliferation related developments in the world, resulting in a new period of safeguards development. As a member of state of the IAEA, we attempted to do the supporting for IAEA's strengthem safeguards. CIAE Safeguards laboratory operates a diversity of NDA and DA equipments for nearly all analytical tasks within the scope of our experimental work and environmental monitoring. Gamma ray spectrometry multichannel analyzer, Neutron counting and physical property measurement etc have been applied for the control of nuclear materials processes. Elemental and isotope analysis have been made the significant progresses in the past ten years in CIAE safeguards laboratory. Inductively coupled plasma optical emission spectrometry (ICP-OES), energy dispersive X-ray fluorescence (XRF) are used for the determination of the impurities elements. The methods using quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and MC-ICP-MS for the measurement of the low-level concentration and isotopes of uranium, thorium and plutonium in environmental samples and nuclear materials have been set up, isotope dilution, and uncertainty discussed in the results. The anion resin, novel extraction chromatograph methods and argon-pressurized extraction column have been developed for the separation of trace radionuclides in the complexes system. In March 2001, a secondary ion mass spectrometry (SIMS) was installed and uranium isotopic ratio results of U-bearing particles have been studied. Thermal ionisation mass spectrometry (TIMS) is an internationally recognised analytical reference technique. Detailed study described for the determination of the isotopic composition and concentration of plutonium by the isotope dilution mass spectrometry (IDMS) using TIMS. The relative expanded uncertainty was 0.2% for the isotopic composition and 0.3% for the concentration of plutonium at 95% confidence level. (authors)