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Minor actinides

  • Transmutation studies for the wastes produced in nuclear power plants are mainly concerned with minor actinides (Americium and Curium). Many isotopes of these minor actinides can be burnt through fission induced by fast neutrons in critical (FNR - fast neutron reactors) or sub-critical (ADS) reactors. To simulate the operation of these reactor incinerators, it is necessary to well know the neutron induced cross-sections for these actinides.
    Thanks to our experience acquired during the studies on neutron data for ^{233}Pa by transfer reaction, we can consider studying the nuclei that were earlier inaccessible by neutron induced reaction due to the very high radioactivity of the targets.

Our programme

  • Direct measurements of fission cross-sections induced by neutrons (from 0.1 to 10 MeV) on ^{241,243}Am nuclei. These experiments are set up with the accelerators of CENBG (AIFIRA) and IRMM of Geel.
  • Determination of fission cross-sections for multiple isotopes of Americium (239,241), Curium (240, 241, 242, 243 and 244) and Plutonium (239) by transfer reactions.
    These experiments are carried out at tandem accelerator of IPNO.
  • The concept of incinerators also necessitates the good knowledge of isotopic distribution of fission products that emit delayed neutrons or can be neutron poisons. Our participation in the experiment (at GANIL) using the transfer reaction technique in inverse kinematics will allow to measure the isotopic yields for many minor actinides (^{241,243}Am et ^{244}Cm).

    This experimental programme is coupled to a complete evaluation of neutron data for these nuclei. This evaluation consists in the development of a statistical model capable to reproduce all the de-excitation channels of the nucleus excited through the capture of fast neutrons (from 0.01 MeV to 20 MeV). The aim of this evaluation is the determination of certain cross-sections (n,γ), (n,n’) and (n,2n) for which direct measurements are extremely difficult.