Variable moderation high performance light water reactor (VMHWR)

A new flow model of high performance light water reactor (HPLWR) is discussed in the present study. HPLWR involves a negative density reactivity coefficient with high time delay. This factor decreases the stability of such reactors when transient and abnormal accidents happen. A new design for enhancing safety and efficiency in such reactors is presented. In the new design, the fluid passing through the moderator channels and the assembly gaps (known as a moderator) flows in channels detached from coolants. It is possible to control the moderator mass flux. Increasing or decreasing the moderator mass flux will modify the moderation capacity, which results in a change in the reactor power. The new model is known as variable moderation high performance light water reactor (VMHWR). In order to analyze the new model, neutronic/thermal-hydraulic coupling is used. The changes happening to the VMHWR parameters in response to the changes in the moderator mass flow rate are reported.