A Theoretical Study of Energetic Interactions Between High Temperature Molten Materials and a Low Temperature Fluid

Analytical models have been developed to predict the hydrodynamic transients resulting from the energetic interactions between a high temperature molten material and a low temperature liquid coolant. Initially, the molten material at high temperature and pressure is separated from the low temperature fluid by a solid metal barrier. Upon contact between the molten material and solid barrier, thermal attack occurs eventually resulting in a loss of barrier integrity. Subsequently, the molten material is injected into the liquid pool resulting in energetic interactions. The analytical models have integrated a wide variety of potentially mutually-interacting transport phenomena which dominate the transient process into a deterministic scheme to predict the hydrodynamic transient process. The model calculations have been compared with the existing experimental results to show its engineering accuracy and adequacy in predicting such energetic interactions. In addition, sensitivity analyses have been performed for the models by varying the values of the major parameters to justify the values of parameters assumed in the numerical calculations. Two models have been formulated to bracket the transport of molten material to the rupture site for the reactor system. The stratified model minimized the rate of transport of material to the break location while the dispersed model maximized such transport. These two models have been applied to a reference pressure tube reactor to evaluate the pressure transients and the potential structural damages as a result of a postulated severe primary coolant blockage in a power channel. The results of the analyses indicated the following: (1) up to 12 adjacent pressure tubes could be permanently deflected, (2) up to all of the calandria tubes could be collapsed onto their associated pressure tubes, (3) the calandria vessel integrity would not be threatened by the hydrodynamic transient