Enhanced passive safety for pressure tube reactors cooled with supercritical water

Operating water-cooled reactors at supercritical conditions results in significant savings because of increased thermodynamic efficiency and plant simplifications. One of the supercritical water-cooled reactor concepts adopts the pressure tube design, and is a natural evolution of CANDU reactors. For the CANDU supercritical water reactor concept, an additional benefit can be realized due to the need to modify the pressure tube design to accommodate the higher coolant temperature and pressure. This modified pressure tube design allows the use of a passive moderator cooling loop to reject moderator heat under normal and accident conditions. This passive loop replaces the existing pumped loop design, and results in enhanced passive safety with the potential for additional cost reductions. (author)