| dc.description.abstract | A major appeal of sodium fast reactors is their passive safety capabilities. To demonstrate this, a series of Loss of Flow WithOut Scram (LOFWOS) tests were conducted at the Fast Flux Test Facility (FFTF) under different reactor power levels. Experimental results from this test were made available through IAEA CRP I32011 for use in a code benchmarking activity. In this work, the System Analysis Module (SAM) was used to analyze the response of the FFTF during one of the LOFWOS transients (Test #13). Efforts were made first to develop a faithful representation of the facility and its main components and control systems. The model was used to predict the steady-state conditions of the plant. The results were compared with provided experimental data, confirming the predictions to be in overall satisfactory agreement. Flow rates and pump head were matched to experimental values within 0.2% in each loop. Additionally, the core inlet temperature was matched within 0.2%. The validated SAM model was then used to predict the thermal-hydraulic response of the system during the first 900 seconds after the initiation of the LOFWOS transient. Selected parameters of interest (system mass flow rate, select core assembly outlet temperatures, primary loop hot and cold leg temperatures, and fission power) were compared to experimental results, revealed at the end of the blind phase of the benchmark activity. The results of the first phase of this benchmark exercise were promising, confirming the ability of the SAM code and the adequacy of the model to capture the general trend of the physical phenomena observed during the transient. Deviations from the experimental results were also identified. An additional SAM simulation was executed using updated boundary conditions taken from the experimental results to further improve the overall predictions and agreement with the experimental results. | en |
