After a half-century hiatus, thorium has returned to the front lines of nuclear power research as a source of fuel. In 2025, China plans to start building a demonstration thorium-based molten-salt reactor in the Gobi Desert. The 10-megawatt reactor project, managed by the Chinese Academy of Sciences’ Shanghai Institute of Applied Physics (SINAP), is scheduled to be operational by 2030, according to an environmental-impact report released by the Academy in October. The project follows a 2-MW expe...