Analysis of aerosol deposition in PHEBUS containment during FPT-1 experiment

The international PHEBUS-FP programme was initiated in 1988 and performed by the French Institute de Protection et de Surete Nucleaire (IPSN) to investigate the key phenomena of severe water reactor accident. The main objective of the programme is to study the release, transport and retention of fission products in an in-pile facility under conditions representative of a severe accident in a light water reactor. The Lithuanian Energy Institute has joined the programme in 2005 and most of the efforts were directed to investigation of containment phenomena. This paper presents overview of the analyses performed to investigate aerosol transport and deposition phenomena in PHEBUS containment during FPT-1 test. A lumped parameter code COCOSYS was used for the analysis. Parametric analyses were performed to investigate the influence of aerosol density, solubility and diffusive boundary layer thickness on the deposition rate and deposition distribution of particles in PHEBUS containment. The performed analysis showed only minor influence of the selected parameters on the results of FPT-1. Also it was observed that the diffusive boundary layer thickness should not be defined too small.