Development and assessment of CFD models including a supplemental program code for analyzing buoyancy-driven flows through BWR fuel assemblies in SFP complete LOCA scenarios

• Main Author: Artnak, Edward Joseph
• Format: Others
• Language: English
• Published: 2013
• Subjects: CFD; CFD Model; Buoyancy driven flow; Buoyancy flow; FLUENT; FLUENT CFD; SNL; Sandia National Laboratories; SFP LOCA; Spent fuel pool loss of coolant accident; SFP loss of coolant; BWR fuel assembly; CAD Model; SolidWorks SFP Model; SFP BWR fuel assembly; NRC; MATLAB; MATLAB SFP Model; 9x9 BWR fuel assembly; MELCOR; MELCOR SFP; 250 million cells; Hydraulic flow loss; Loss coefficients; Buoyancy flows; MELCOR calibration; Pressure loss; BWR pressure loss; SFP airflow; SNL fuel assembly
• Online Access: http://hdl.handle.net/2152/ETD-UT-2012-12-6836

This work seeks to illustrate the potential benefits afforded by implementing aspects of fluid dynamics, especially the latest computational fluid dynamics (CFD) modeling approach, through numerical experimentation and the traditional discipline of physical experimentation to improve the calibration of the severe reactor accident analysis code, MELCOR, in one of several spent fuel pool (SFP) complete loss-of-coolant accident (LOCA) scenarios. While the scope of experimental work performed by Sandia National Laboratories (SNL) extends well beyond that which is reasonably addressed by our allotted resources and computational time in accordance with initial project allocations to complete the report, these simulated case trials produced a significant array of supplementary high-fidelity solutions and hydraulic flow-field data in support of SNL research objectives. Results contained herein show FLUENT CFD model representations of a 9x9 BWR fuel assembly in conditions corresponding to a complete loss-of-coolant accident scenario. In addition to the CFD model developments, a MATLAB based control-volume model was constructed to independently assess the 9x9 BWR fuel assembly under similar accident scenarios. The data produced from this work show that FLUENT CFD models are capable of resolving complex flow fields within a BWR fuel assembly in the realm of buoyancy-induced mass flow rates and that characteristic hydraulic parameters from such CFD simulations (or physical experiments) are reasonably employed in corresponding constitutive correlations for developing simplified numerical models of comparable solution accuracy. === text