Position Paper on the Use of Thorium in the Nuclear Fuel Cycle - How Should Thorium be considered in the GIF? -2010

This paper, prepared by the GIF Experts Group (EG), explores the potential of thorium as a viable alternative in the nuclear fuel cycle, particularly within the context of Generation IV nuclear systems. Thorium, a naturally abundant element with unique physical properties, has garnered attention due to its potential for reducing long-lived radioactive waste and mitigating proliferation risks when used in combination with uranium. The paper reviews the resources, physical properties, and the role of thorium in both open and closed fuel cycles. It also examines the technical and economic feasibility of using thorium-based fuels in current and advanced nuclear reactors, including Light Water Reactors (LWRs), Heavy Water Reactors (HWRs), and Molten Salt Reactors (MSRs). Additionally, the proliferation potential associated with thorium-based fuels is critically assessed, along with the challenges of reprocessing and recycling. The paper concludes by suggesting that thorium's integration into the nuclear fuel cycle should be explored further through targeted research and development, with an emphasis on symbiotic reactor fleets and molten salt reactor technologies.