- The reactor core is modelled by parallel cooling channels describing one or more fuel assemblies. The parallel channels are coupled hydraulically by the condition of equal pressure drop over all core channels.
- A one- or two-phase coolant flow model on the basis of four differential balance equations for mass, energy and momentum of the two-phase mixture and the mass balance for the vapour phase allows the description of thermodynamic non-equilibrium between the phases.
- Time-dependent thermo-hydraulic boundary conditions for the core like coolant inlet temperature, pressure, coolant mass flow rate, or pressure drop can be given as input or obtained from the coupled thermohydraulic system code.
- Heat transfer regime from one-phase liquid flow up to post critical heat transfer and superheated steam
- Constitutive laws for heat, mass, and momentum transferr
- vapour generation at heated walls
- condensation in the subcooled liquid
- phase slip ratio
- pressure drop at single flow resistances and friction along the flow channels
- IFC-67 water and steam properties
- Various correlations for the critical heat flux
- Consideration of hot channels with given power peaking factors connected to selected fuel assemblies during the transient calculation
- Coupling with mixing models for the downcomer and lower plenum and CFD for providing detailed boundary conditions at the core inlet