The Integrated Safety Assessment (ISA) methodology, developed by the Spanish Nuclear Safety Council (CSN), has been applied to a thermo-hydraulical analysis of a Westinghouse 3-loop PWR plant by means of the dynamic event trees for a Medium Break Loss of Coolant Accident (MBLOCA). The ISA methodology allows obtaining the damage domain for each sequence of the MBLOCA event tree as a function of the break area and the operator actuation time needed to cool down and depressurize reactor coolant system by means of steam generators. Simulations are performed with an interconnected functional block of codes named Dendros, Babieca, MAAP and SIMPROC. Each of them respectively is required to: dynamically generate the event tree stemming from an initiating event, drive the simulation, calculate the thermo-hydraulic variables in the nuclear power plant (NPP), and incorporate the operator procedures. The results show the capability and necessity of the ISA methodology, or similar, in order to obtain accurate results that take into account time delays and parameter uncertainties.
Medium Break Loss of Coolant Accident (MBLOCA) Integrated Safety Assessment (ISA) Dynamic Event Tree (DET) Probability Calculation Damage Domain.
C. Queral J. M. Izquierdo J. Hortal M. Sánchez-Perea E. Meléndez J. Gil I. Fernández J. J. Gómez S. Murcia L. Ibá(n)ez J. González-Cadelo I. Ca(n)amón G. Rodríguez-Martín J. Elorza A. Hidalgo A. López C. Conde
Universidad Politécnica de Madrid (UPM) c/ Alenza 4, 28003 Madrid, Spain. Consejo de Seguridad Nuclear (CSN) c/ Justo Dorado 11, 28040 Madrid, Spain Indizen Technologies S.L. Av/ Pablo Iglesias 2-3oB-2, 28003 Madrid, Spain. Indizen Technologies S.L.Av/ Pablo Iglesias 2-3oB-2, 28003 Madrid, Spain.