Thermal hydraulic analysis of a passive residual heat removal system

A theoretical investigation on the thermal hydraulic characteristics of a new type of passive residual heat removal system (PRHRS) for an integrated pressurized water reactor is presented in this paper. The residual decay heat of the reactor core should be removed safely through multi-interknit natural circulation loops on the occasion of normal or accidental reactor shutdown. A one-dimensional model and a simulation code are developed to theoretically predict the transient behavior of the PRHRS. It is found that the calculated parameter (such as heat transfer capacity, pressure and mass flow rate) variation trends are reasonable. The decay heat can be safely removed by the PRHRS. However, the peak value of the secondary loop pressure is higher than the expected one. A protection measure of the secondary loop pressure should be considered in the model. (authors)