Integral model of the NPP Krško containment and the PCFV system for the MELCOR code

Modeliran je pasivni sustav za filtriranje i ventiliranje zaštitne zgrade (PCFV). U slučaju teške nesreće, zrak prolazi kroz aerosolne filtre i jodni filtar gdje se talože fisijski produkti. Nakon filtracije, zrak se ispušta u okoliš pri čemu dolazi do pada tlaka u zaštitnoj zgradi. Snižavanje tlaka bitno je radi očuvanja integriteta zaštitne zgrade. Proučeno je stacionarno stanje PCFV sustava. Integriran je model PCFV-a u već postojeći model reaktorske zgrade NE Krško i primijenjen na tranzijentni izračun gubitka unutrašnjeg i vanjskog izmjeničnog napajanja. Posebna pažnja pridala se tlaku i temperaturi sustava te protoku, temperaturi i sastavu ispušnih plinova.Passive Containment Filtered Vent (PCFV) is modelled. In the case of a severe accident, air passes through the aerosol filters and the iodine filter where fission products are settled. After filtrating, air is released in the environment which reduces the pressure in the containment building. Reduction of pressure is crucial for preservation of building integrity. Steady state of the PCFV is studied. PCFV model is integrated with the NPP Krško containment and transient response is calculated for the loss of internal and external AC supply. Attention was given to pressure and temperature of the system as well as to mass flow, temperature and composition of exhaust gases