Ruthenium transport in an RCS with airborne CsI

Ruthenium is one of the most radiotoxic fission products which can be released from fuel as ruthenium oxides in an air ingress accident at a nuclear power plant. In this study it was found that the transport of the released ruthenium oxides through a reactor coolant system into the containment building is significantly affected by the atmospheric conditions. Airborne CsI increased the transport of gaseous ruthenium compared with that in a pure air atmosphere. The overall transport of ruthenium increased with temperature. In order to understand the behaviour of ruthenium in accident conditions, it is important to widen the experimental conditions from pure air/steam atmospheres to more realistic mixtures of prototypic gases and aerosols.