• demo
• fusion
• lofa
• melcor
• thermal hydraulics
• wcll

The thesis deals with the development and set-up of a specific MELCOR 1.8.6 Fusion Version nodalization of WCLL DEMO PHTS (Primary Heat Transfer System) able to analyze the transient behavior of the facility in case of Loss Of Flow Accident (LOFA). The focus is given to the accidental overpressure and temperature in the loop, in particular in the most loaded modules, to the temperature of the heat structures, to the mass flow rate of the pump and on decay heat. This activity has been concluded through sensitivity analysis on rupture area, rupture disks’ opening pressure and cross-section’s dimension aimed at investigating the behavior of the system and at supporting the design of the plant.