  ODS steels based on yttrium oxide have been suggested as potential fusion
reactor wall materials due to their observed radiation resistance properties.
Presumably this radiation resistance can be related to the interaction of the
particle with vacancies,self-interstitial atoms (SIAs) and other radiation
damage debris. Density functional theory has been used to investigate this at
the atomic scale. Four distinct interfaces, some based on HRTEM observations,
between iron and yttrium oxide were investigated. It is been shown that the
Y$_2$O$_3$-Fe interface acts as a strong trap with long-range attraction for
both interstitial and vacancy defects, allowing recombination without altering
the interface structure. The catalytic elimination of defects without change to
the microstructure explains the improved behaviour of ODS steels with respect
to radiation creep and swelling.
