Effect of Thermal Stratification of Coolant in a Vertical Heated Channel

In a vessel type low power research reactor having vertical fuel plates, while circulating pump is switched off, coolant (light water) would flow by natural convection. By using conservation equations, taking into account simplifying assumptions, coolant mass flow rate through the channel can be obtained. Due to the thermal stratification effect, coolant mass flow rate through the channel is shown to decrease. The present study shows that, assuming a linear thermal stratification, the variations of coolant mass flow rate versus stratification parameter behave in a non-linear manner. The aforementioned variations decrease down to 41%.