Mathematical model of the reactor core for the MELCOR code

Program MELCOR primarno služi za analizu nesreća u nuklearnim elektranama. Na temelju izrađenog modela elektrane mogu se simulirati različiti normalni pogonski i izvanpogonski slučajevi kao što je potpuni gubitak napajanja -SBO (engl. Station Blackout). Ispravnost modela reaktorske posude i jezgre je od iznimne važnosti jer tamo za vrijeme nesreće dolazi do najkompleksnijih pojava – degradacija, taljenje i relokacija jezgre, oksidacija obloga goriva i proizvodnja vodika. Ovaj rad uspoređuje utjecaj različitih modela reaktorske posude i jezgre na rezultate termohidrauličkog odziva elektrane za vrijeme teške nesreće – SBO.Primary use of MELCOR code is to analyse accidents in nuclear power plants. Based on made model of nuclear power plant it is possible to simulate normal operation or off-normal operation of nuclear power plants – Station blackout. Accuracy of mathematical model of reactor pressure vessel and core is of exceptional importance because that is where, during the accident, the most complex phenomenons take place – degradation, melting and relocation of the core, oxidation of the fuel cladding and hydrogen production. Subject of this paper is comparison of difderent models of reactor pressure vessel and core and effects it has on the results of thermohydraulic response of nuclear power plant in case of severe accident – SBO