Sensing ruthenium tetroxide Emissions : a spectroscopic study

Abstract : After the Fukushima accident, it became essential to have a way to monitor in real time the evolution of a nuclear reactor during a severe accident, in order to react efficiently and minimize the industrial, ecological and health consequences of the accident. Ruthenium is a low volatile fission product but in case of the rupture of the vessel lower head by the molten corium, the air entering into the vessel oxidizes Ru into a gaseous form RuO$_4$. To monitor the presence of RuO4 allows making a diagnosis of the core degradation and quantifying the potential release into the atmosphere. RuO$_4$ is of prime importance since it can have a significant radiological impact. Here, we present the study of the feasibility of the monitoring by an optical measurement.