Fluxnium Targets Seawater to Solve Nuclear Fuel Shortages

The U.S. faces a structural shortage of uranium as it attempts to triple its nuclear capacity by 2050. Most current supply originates from geopolitically sensitive regions including Russia, Kazakhstan, and Niger. To bridge this gap, Fluxnium, led by serial entrepreneur Jeff Green, recently secured $7 million in seed funding from investors including Constellation Energy. The startup aims to transform the economics of nuclear fuel by harvesting uranium directly from the sea.

Fluxnium utilizes polymer fibers licensed from U.S. Department of Energy national labs. These fibers, configured into braided lines, are deployed at sea and left to soak for up to 60 days. The material attracts dissolved uranium, which is then purified into yellowcake once retrieved. While early lab demonstrations placed extraction costs at over $200 per pound—well above current market rates—the company is focused on scaling fiber surface area to achieve price parity with traditional mining. Green emphasizes that the process avoids the toxic tailings associated with hard-rock mining, offering a cleaner alternative that integrates directly into existing nuclear supply chains.