Fluxnium Targets Seawater Uranium to Hedge Against Supply Volatility

The U.S. aims to triple its nuclear power capacity by 2050, but rising costs for yellowcake—which the U.S. Energy Information Administration reports have climbed 75% over five years—and geopolitical reliance on nations like Russia, China, and Kazakhstan pose significant risks. To address this, clean tech startup Fluxnium is developing a method to extract uranium from seawater, a resource Jeff Green, Fluxnium founder and CEO, tells TechCrunch contains over 4 billion metric tons of uranium, as TechCrunch first reported.

Using chemistry licensed from U.S. Department of Energy national labs, Fluxnium employs specially designed polymer fibers that attract dissolved uranium. The process involves deploying braided fibers from buoys, similar to seaweed farming, for 30 to 60 days before bringing them ashore for extraction. While early national lab demonstrations saw costs exceed $200 per pound—more than double current Western supplier prices—Green says Fluxnium is reducing costs by increasing the surface area of the fibers.

The company's primary objective is to drive costs out of the supply chain to make seawater extraction competitive with traditional hard rock mines. Fluxnium recently emerged from stealth after closing a $7 million seed round. The funding was led by Congruent Ventures, with participation from Active Impact Investments and Constellation Energy, the operator of the largest nuclear fleet in the U.S.