Modeling Fission Product Vapor Transport in the Falcon Facility
An extensive database of aerosol experiments exists and has been used for checking aerosol transport codes. Data for fission product vapour transport are harder to find. Some qualitative data are available, but the Falcon thermal gradient tube tests carried out mark the first serious attempt to provide a set of experiments suitable for the validation of codes that predict the transport and condensation of realistic mixtures of fission product vapours. The results showed that once the vapours condense on to aerosols, VICTORIA can predict their deposition rather well. VICTORIA assumes that the physical properties of the aerosol are independent of its composition and that each particle has the same composition. This assumption is justified for these experiments. The behaviour of the vapours is harder to interpret. Essentially, it is important to know the temperature at which each element condenses. In general, VICTORIA predicted that, with the exception of cesium, there would be less variation in the speciation, and hence, variation in the deposition, between tests than is in fact observed. If the observed differences in deposition patterns were indeed caused by variations in speciation, then it must be concluded that, under the conditions of the Falcon experiments studied, the thermochemical database is incomplete or not sufficiently accurate. VICTORIA underpredicts the volatility of most elements, and this is partly a consequence of the ideal solution assumption and partly an overestimation of vapour/aerosol interactions.
Bibliographic Reference: Article: Nuclear Technology, Vol. 110, (1994) pp. 181-197
Record Number: 199610019 / Last updated on: 1996-02-16
Original language: en
Available languages: en