An Empirical Mixing Model for Pressurized Thermal Shock Applications

Empirical correlations are developed for the local temperature and velocity distributions in the pressurized water reactor downcomer for pressurized thermal shock scenarios. The correlation is based on Creare test data and has been validated with Science Applications, Inc. experiments and COMMIX code calculations. It provides good agreement under pump flow and natural circulation conditions and gives a conservative estimate under stagnation conditions.