Thorium is a naturally occurring, slightly radioactive metal that holds significant potential as a clean, safe, and abundant energy source for the world’s future. Unlike traditional uranium-based nuclear fuel, thorium offers advantages in sustainability, waste reduction, and proliferation resistance, making it an increasingly important subject in discussions about advanced nuclear energy.

This encyclopedia explores thorium’s properties, history, applications, and its role in next-generation power technologies, providing a comprehensive resource for anyone seeking to understand what thorium is and why it matters to the future of global energy.