The assessment of the safety of presently operating reactors, reactor
modifications and changes of the mode of operation rely on accurate
calculations for predictability and understanding of reactor operation.
The understanding of the neutron spectrum and the calculation of the number of
prompt emitted neutrons have been improved by taking into account the most
recent advances in the theory of the fission process based on the multi modal
fission theory.
To fully apply this model a much better knowledge of the fission fragment
yields and total kinetic energy distributions is needed. IRMM has been one of
the leading laboratories in the determination of fission yield distributions
as a function of incident neutron energy for certain major and minor
actinides. This work is being performed in close collaboration with
theoretical groups all over the world who are improving their model
descriptions by applying the experimental results obtained at IRMM.
Another important aspect of reactor safety is the integrity of structural
components. It is governed by the number of displacements per atom and gaseous
inclusions, which demand the study of neutron induced production of light
charged particles, in particular H and He. These cross-sections are studied at
IRMM measuring either directly the neutron induced reaction, or using the
neutron activation technique.