SIMS characterisation of actinide isotopes in irradiated nuclear fuel

SIMS analysis of an UO2 fuel irradiated at low temperature to 65MWd/kgHM

“…237 Np is also a decay product of 241 Am and about 15% of the Np present was formed by this route. In a similar SIMS study carried out concurrently with this one by Desgranges et al [26] the radial distribution of 237 Np was also found to differ from that of the other actinide isotopes measured. The isotopic composition of plutonium obtained from the radial distribution of the isotopes measured by SIMS (Fig.…”

Simultaneous Isotopic Analysis of U, Pu, and Am in Spent Nuclear Fuel by Resonance Ionization Mass Spectrometry

“…The neutron energy distribution varies from the center to the edge of the pellet, with the result that the region within a few hundred microns of the edge is exposed to a higher flux of epithermal neutrons, which induce the creation and subsequent fission of 239 Pu and drive higher burnup per unit volume. This is the skin effect and is reflected in the radial distribution of actinides and fission products within a pellet, which show higher concentrations of burnup products within a few hundred microns of the pellet edge. , Therefore, two samples from the same pellet can and do show significantly different actinide elemental and isotopic compositions.…”

Secondary Ion Mass Spectrometry

“…106,111 Another field of fruitful applications is the inventory of actinides produced in irradiated UO 2 and MOX fuels. 106,112 Research in this field has enabled the study of the evolution of major U and Pu isotopes as well as minor actinide isotopes (Np, Am, Cm) in relation to nuclear reactions (fission, neutron capture and decay reactions) and has fed and validated neutron and fuel behaviour codes developed for industrial nuclear reactors.…”