Aerosol formation during air ingress into the core of a pebble high temperature reactor

This project investigates the aerosols formed during a simulated air ingress into the core of a high temperature gas cooled reactor. To do this a test device has been set up containing 12 spherical graphite elements 60 mm in diameter. Mass concentration of the graphite particles in the reaction gas, and size distribution of the equivalent aerodynamic diameter, are determined as a function of pebble bed temperature, stream velocity and corrosion time. After measuring with an impactor, the graphite particles are analysed with the aid of a scanning electron microscope. The particles sampled out of the gas stream are irregularly shaped. The measured surface distribution functions for particles from each impactor stage can be used to calculate dynamic shape factors and adsorption terms for fission product transport to the particle surface. (author)