Time Evolution Simulation for a Realistic In-containment Source Term During Hypothetical Accidents

The time evolution of an iodine (as a key and representative volatile fission product species) transport and removal is simulated to evaluate a realistic in-containment source term instead of TID-14844 under a conservative hypothetical scenario in PHWRs. Fission products in vapor and aerosol forms can be deposited onto every heat sink in a compartment and be dissolved in a water pool by different deposition mechanisms. All these reactions governing an iodine development and evolution in a containment under severe accident conditions are simulated by using the latest ISAAC 2.x version which includes modified iodine release/transport/deposition models.