Critical Power Evaluation with Consideration of Differences in Droplet Behavior due to Spacer Shape Infuence
An evaluation method for droplet deposition coefficients, corresponding to spacer shapes, was developed in order to predict nuclear fuel bundle critical power. The method is based on a three-dimensional numerical analysis of dispersed flow around the spacer. The analysis showed that coolant droplet deposition characteristics onto fuel rods differed between grid type and ferrule type spacers, and also between fuel rods due to flow tabs on the upper end of the spacer band. The droplet deposition coefficient was modeled from the analysis results and adopted into a critical power prediction code based on subchannel analysis. Comparisons between critical powers calculated by the subchannel analysis code and those measured with full-scale test assemblies showed good agreement and improved prediction accuracy of the code.
- Journal of nuclear science and technology
Journal of nuclear science and technology 32(4), 301-312, 1995-04-25
Atomic Energy Society of Japan