Numerical computation of underwater explosions due to Fuel-coolant interactions

Abstract

Calculations have been carried out to investigate the feasibility of using approximate acoustic methods to describe the transient pressure field produced by the rapid expansion of a high pressure vapor bubble generated by an energetic steam explosion. The approximate methods are validated by comparing with exact finite difference calculations. The calculations illustrate the importance of compressibility effects in reducing the peak overpressure between the leading shock and subsequent bubble collapses. The acoustic method is applied to estimate the pressure transients following a hypothetical large-scale corium-water explosion. The calculations provide a more realistic estimate of the pressure transients than methods that scale the blast overpressures and impulses in terms of the total thermal energy available. To obtain a more accurate estimate of the pressure generated, the finite pressurization time, transient phase change effects and bubble instabilities must be considered. © 1994.