Modelling of fission products release in VERDON-1 experiment with cGEMS: Coupling of severe accident code MELCOR with GEMS thermodynamic modelling package

The treatment of chemistry and thermodynamics in the integral severe accident codes is typically limited. A more accurate during modelling is, therefore, great interest. For this purpose, work focused on development coupling MELCOR code with chemical thermodynamic calculations using GEMS HERACLES database. Developed between two codes, called cGEMS, allowed for improved description fission product release from nuclear fuel under conditions. VERDON-1 test was selected as an experimental reference simulations. Experimental behaviour Mo, Cs Ba observed experiment reproduced by developed coupled code. Performed simulations provided detailed information about speciation at different redox obtained provides a accidents.