Investigation on scaling law for reactor natural circulation under motion conditions

For some Pressurized Water Reactors (PWR) operated on automobiles, boats or deep sea vessels, natural circulation simulation is important for understanding their safety during severe accidents, or system characteristics when natural circulation is adopted instead of the primary pumps to drive coolant in their loops. Based on the scaling laws of natural circulation for stationary reactors, the scaling laws for moving conditions are derived in this paper by analyzing accelerations and their distribution in a moving reactor with rigid motion theory, and introducing these accelerations into the momentum equations representing a one-dimensional natural circulation model. With modified equations, a set of motion simulation criteria was obtained, and equal height simulation and unequal height simulation were studied. A reduced height simulation is helpful for ensuring that three-dimensional phenomenon are reproduced, but time scaling is needed in a motion simulation.