Assessment of a Self-Sustaining Fuel Cycle Option for a Pressure-Tube Heavy Water Nuclear Reactor

Nuclear energy is an excellent power source for stable, clean-air, baseload electricity generation. The pressure tube heavy water reactor (PT-HWR) is a proven design with extensive operational experience and has great flexibility in the type of nuclear fuels and fuel cycles that can be used. Thorium is a relatively abundant alternative fuel that could help complement and eventually replace uranium. The objective of this work was to evaluate a potential heterogeneous seed/blanket PT-HWR core concept that may be able to achieve a self-sustaining thorium fuel cycles. It was found that very high-conversion, nearly sustainable cores which breed up to 99.06% of the required fissile fuel can be achieved. In addition, this concept can allow a PT-HWR to operate at a power level that is 10% higher than those currently operating with natural uranium (NU) fuel. Options for future studies such as coupling this reactor concept with others providing makeup fissile uranium fuel, are discussed.