Computer code development programs at JAERI on fission product behavior

As a part of computer code development programs on severe accident analysis, computer programs HORN and REMOVAL, are being developed for analysis of fission product release and transport in primary coolant system and containment vessel. HORN is designed to calculate fission product release and transport in primary coolant system and the code is capable of predicting chemical forms of volatile fission products in a leak path based upon equilibrium assumptions. REMOVAL is to calculate aerosol removal by natural mechanisms as well as engineered safety features in the containment vessel. The model includes steam condensation onto aerosol particles. Results of sensitivity analyses are presented along with description of the models used in each code