Numerical investigation of transport, deposition and re-entrainment of aerosol particles
In a high temperature pebble-bed reactor core, the friction between graphite elements triggers the formation of carbonaceous dust. During reactor operation fission products diffuse into the graphite material and the carbonaceous dust subsequently becomes carrier of fission products. The dust is eventually conveyed by the cooling carrier phase and deposits in the primary circuit of the high temperature reactor. In hypothetical severe accident, a dose of radioactive material dust may escape the system boundaries. The turbulent flow structures of the coolant contribute significantly to deposition and re-entrainment of nuclear aerosol particles. Numerical modeling of these complex transport mechanisms are therefore of key importance to nuclear safety.
Numerical methods based on the Euler-Lagrange approach are currently being developed to accurately predict transport, deposition and re-entrainement of aerosol particles. Particle transport in a turbulent obstructed channel flow can be seen in Figure 1. Various experiments are being performed to validate the simulation results. Am early study already shows good agreements between numerical and experimental data (Figure 2).
This work is supported by the European Commission under Grant 249337 of the “Thermal-Hydraulics of Innovative Nuclear Systems” project.
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