Damage Domains Calculation Associated With Multiple Damages in a Steam Generator Tube Rupture Dynamic Event Tree

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 (DET) for Steam Generator Tube Rupture (SGTR) sequences. The ISA methodology allows obtaining the Damage Domains of a SGTR Dynamic Event Tree taking into account the operator actuation times and system response time. The Damage Domains allow to quantify more exactly the risk associated with the sequence even if the contribution to the total risk is due to multiple damages, like dose and core damage in the case of a SGTR. The results shows the impact of the risk associated with the dose as an addition of the risk associated with the core damage. Simulations are performed with SCAIS (Simulation Code system for Integrated Safety Assessment), which includes a dynamic coupling with MAAP thermal hydraulic code.