Thermal-hydraulic transient analysis of the FFTF LOFWOS Test #13

In the framework of a Coordinate Research Project (CRP) endorsed by International Atomic Energy Agency (IAEA), Department Astronautical, Electrical and Engineering (DIAEE) Sapienza University Rome has developed thermal–hydraulic model Fast Flux Test Facility (FFTF). FFTF was Sodium-cooled Reactor (SFR) Westinghouse Electric Corporation for U.S. Energy, which operated from 1980 to 1992. The main mission reactor prove feasibility operation SFR nuclear power plants. For this purpose, designed as flexible system extensively instrumented, making it attractive code validation purposes. proposed benchmark exercise involves Loss Of Flow Without Scram (LOFWOS) test, performed in 1986. DIAEE is validating multiphysics modelling based on Neutron-Kinetic/Thermal-Hydraulic (NK/TH) coupling approach with RELAP5-3D© PHISICS codes. present paper deals assessment standalone TH modelling, establishing basis next NK/TH phase. Steady-state results have been compared specifications, proving adequacy calibration. After that, comparison between transient simulation experimental data highlighted an overall good agreement, demonstrating capability nodalization reproduce LOFWOS #13. Outside parameters selected exercise, outlet plenum thermal stratification sodium free surface motion within Gas Expansion Modules (GEM) analysed, providing useful outcomes understanding event future perspectives.