Debris-bed quench characteristics under bottom-flood conditions

Light water reactor degraded core accident sequence studies postulate the existence of superheated core debris beds within the reactor vessel. From both the accident management viewpoint and the accident evaluation viewpoint, it is necessary to understand the quench characteristics of such a degraded core. In particular, the SCDAP code, which is intended to model the core response during a severe accident condition, must be able to predict the thermal-hydraulic state of the core as a function of time when the core is in a degraded (debris bed) state. At present, the SCDAP code does not have a debris bed quench model. This program is therefore geared towards developing such a model. The experimental part of the program aids in model development and provides a data base for verifying the transient debris bed quench models. The current work deals with the case of one-dimensional debris bed being quenched by the injection of liquid coolant at a constant rate from the bottom of the debris bed