CFD Analysis of Rewetting Behavior in Nuclear Fuel Rod Bundle with Change in Operating Conditions

Abstract

Abstract Numerical analysis on rewetting of nuclear fuel rod bundle by injecting coolant water in radial jet direction has been performed using Computational Fluid Dynamic (CFD). CFD-CFX results are compared with experimental data and an investigation is carried out for three ranges of numerical operating conditions (central water flow: 150 lpm, 225 lpm and 300 lpm; sub-cooled coolant: 288 K, 298 K and 308 K; initial wall temperature: 430 K, 500 K and 600 K). It was observed that the rewetting behavior shows an irregular pattern of rewetting progress. Rewetting velocity has got no significance under any operating conditions. The effective numerical response is observed for rewetting temperature and wetting delay. Results show an increase in rewetting temperature, and reduction in wetting delay under higher flow rate, low sub-cooling and lowering the initial wall temperature.