Abstract

The chemical composition of aerosols formed by revaporisation and subsequent condensation of fission products and simulant material was investigated using electron microscopy. A stage dedicated only to the collection of aerosol particles on carbon coated copper grids was designed and tested. As raw material for these experiments core material from the TMI-2 accident, fission product deposits from the Phébus FPT3 tests and Cs2MoO4 powder were used. The examination of aerosols was made by transmission and scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results indicate the range of species encountered at different temperatures showed the necessity for a time dependent sampling method. The investigated aerosols were in the nanoparticle range. A clear pattern was found for the use of fission product deposits from the Phébus FPT3 experiments. In oxidising atmosphere in the temperature range of 450K to 910K a species of 2nm sized spherical caesium-rhenium particles were observed that coagulated to spherical about 20nm sized particles. Other elements such as Mo and Te occurred at various temperature ranges and atmospheres. Also the vaporisation of caesium molybdate, as predicted in thermodynamic equilibrium calculations, was examined.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call