MAGIC and Code_Saturne developments and simulations for mechanically ventilated compartment fires

Fire, being the main potential internal hazard in nuclear power plants, Electricité de France (EDF) is dealing with. Fire safety – in all a plant's life stages; from conception to dismantling – will always be therefore an essential factor. In addition to prescriptive requirements in safety regulation, demonstrations are performed continuously using fire codes developed by EDF Research & Development. Modeling equations are subject to foreseen applications. MAGIC is a two zone code based on the assumption of hot and cold layer stratification, and is widely used for fire safety doctrine development, fire zone sectoring and Fire Probabilistic Risk Assessment. Code_Saturne is a general purpose computational fluid dynamics (CFD) software which, among other things, simulates buoyancy-dominated turbulent diffusion flames through a URANS (Unsteady Reynolds Averaged Navier–Stokes) approach, allowing more complex fire scenarios in larger buildings. During the PRISME OECD fire research program, the interaction between fire and ventilation in confined environments was studied. Tests were performed in a concrete multi-compartment building, mechanically ventilated with rooms in connection through open doors or analytical leakages. Hydrocarbon (HTP) liquid pools range from 0.2 to 1m2 and air renewal from 0 to 15Vh−1. PRISME tests highlighted the strong interaction between fire and ventilation and their results were used to upgrade the MAGIC ventilation network model. Good agreement of MAGIC numerical results with measurements, supplemented by sensitivity studies confirms its prediction ability. Code_Saturne validation process for diverse reacting flows is presented and discussed in depth. Furthermore preliminary results for mechanically ventilated fires are also analysed. ► Fire safety will always be an essential factor in nuclear power plants. ► We model the interactions between a fire and a mechanical ventilation system. ► MAGIC is an international two zones code widely used for fire safety analysis. ► Code_Saturne is a CFD software allowing more complex fire scenarios. ► Validation and sensitivity studies offer confidence in our codes capabilities.