Fission product deposition and revaporization phenomena in scenarios with large temperature differences
The precalculations of the Phebus-FP experiments, particularly FPT-0 and FTP-1, have produced a large corpus of calculational results on fission product retention in the presence of large temperature differences between the carrier gas stream and the colder pipe wall. The steam/hydrogen stream laden with fission product vapours, aerosols and structural materials arrives in the steam generator tube at a temperature of 700 C or more, while the tube walls may be at 150 C. Predicted fission product retention is large (30 % or more) with all codes, but the predictions differ widely depending on the balance between the condensation of FP vapours on the wall and aerosol nucleation in the rapidly cooling gas stream and deposition of the aerosol particles by thermophoresis and by inertial impaction, especially in bends. A detailed study has been made of the code models for this situation, and some of the reasons for the differences in predicted retention have been identified. The codes examined are VICTORIA, RAFT and TRAPF. Some comparison with experimental results from the French DEVAP and TUBA experiments is made. The paper includes a short discussion on chemical resuspension, which is predicted in FPT-0 by VICTORIA as a consequence of changes in the carrier gas composition during the experiment.
Bibliographic Reference: Paper presented: 29th ASME/AlChE/ANS National Heat Transfer Conference, Atlanta (US), August 8-11, 1993
Availability: Available from (1) as Paper EN 37325 ORA
Record Number: 199311298 / Last updated on: 1994-11-29
Original language: en
Available languages: en