FINIX - Fuel behavior model and interface for multiphysics applications: Code documentation for version 0.15.12

Timo Ikonen, Joonas Kättö, Henri Loukusa

    Research output: Book/ReportReport

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    The FINIX fuel behavior code has been updated to version 0.15.X. In the new version a new cladding mechanical model is implemented which models time-independent plasticity of the cladding. Material properties for Zr1%Nb cladding have also been implemented in this version.

    The FINIX code has been designed to provide a fuel behavior module for other simulation codes in multiphysics simulations. The intended use is the improvement of fuel behavior description in neutronics, thermal hydraulics and reactor dynamics codes, without having to employ full-scale fuel performance codes. FINIX couples with the host code on a source code level, and provides an interface of functions that can be used to access the fuel behavior model from the host code. At VTT, FINIX has been integrated into the Monte Carlo reactor physics code Serpent 2, and reactor dynamics codes TRAB-1D, TRAB3D and HEXTRAN.

    FINIX consists of several interconnected models that describe the thermo-mechanical behavior of the fuel rod. FINIX solves the transient heat equation, with couplings to the cladding and pellet mechanical behavior through the gap conductance and pressure. Publicly available experimental correlations are used for the material properties, and simple models for the heat transfer from the cladding to the coolant have been included.

    FINIX has been verified against the FRAPTRAN fuel performance code in RIA scenarios, and compared against experimental Halden reactor data. Results indicate good agreement with the FRAPTRAN code and experimental measurements. Limitations of the present version in the simulated scenarios have also been identified. Detailed account of the validation results are presented in a separate validation report.
    Original languageEnglish
    PublisherVTT Technical Research Centre of Finland
    Number of pages144
    Publication statusPublished - 2015
    MoE publication typeD4 Published development or research report or study

    Publication series

    SeriesVTT Research Report


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