FINIX fuel behavior module
FINIX is a novel light-weight fuel behavior code designed specifically for coupled calculations by T. Ikonen at VTT. FINIX solves both the temperature distribution in the fuel rod and the heat flux from cladding to coolant allowing two-way couplings with both neutronics and thermal-hydraulics solvers. While the current capabilities of FINIX are specifically directed to calculating the fuel rods' thermal response in fast transient scenarios, FINIX can also be used to calculate steady state conditions.
The correlations used in FINIX are publicly available. The fuel rod is modeled in FINIX as consisting of separate axial zones that are coupled via the gas gap pressure. The thermal and mechanical models in each of the axial zones are coupled via the gas gap pressure and heat conductance.
FINIX uses the so-called 1.5 dimensional geometry model dividing the active length of the fuel rod into multiple axial zones. In each axial zone the fuel pellet and the cladding are divided into multiple concentric radial rings. The axial coupling between the different zones comes from the coolant temperature boundary condition and rod internal pressure.
Coupling with Serpent
- ^ T. Ikonen, V. Tulkki, E. Syrjälahti, V. Valtavirta and J. Leppänen, "FINIX - Fuel Behavior Model and Interface for Multiphysics Applications", In proc. TopFuel 2013, Charlotte, NC, Sept. 15-19, 2013.