Why the world doesn’t recycle more nuclear waste

France operates the world's largest nuclear waste reprocessing program at its La Hague plant in northern France, which can process about 1,700 tons of spent fuel annually using a method called PUREX that extracts reusable uranium and plutonium. Despite the potential to reduce waste volume and mining demand, reprocessing remains economically unviable for most countries because spent MOX fuel generates excess heat that limits repository storage capacity and the process is expensive, with uranium supplies currently abundant. Heat, not volume, is the key constraint in deep underground storage facilities, meaning reprocessed fuel can occupy as much or more space than untreated spent fuel despite smaller volumes. France maintains its reprocessing program primarily for energy independence and national security, as the country lacks domestic uranium resources, while Japan is constructing its own facility expected to open by 2027 after decades of delays. Experts say geological repositories will remain necessary regardless of recycling efficiency, though new separation technologies could eventually make reprocessing more economically attractive.