Clean-tech startup Fluxnium has raised a $7 million seed round led by Congruent Ventures, with participation from Active Impact Investments and Constellation Energy, to commercialise a method for extracting uranium from seawater, the company told TechCrunch. The ocean holds more than 4 billion metric tons of dissolved uranium, according to Fluxnium, enough to supply roughly 50,000 years of fuel at current demand.
The technology, licensed from U.S. Department of Energy national labs, uses polymer fibres that attract dissolved uranium, braided into long lines and hung from offshore buoys in a setup founder and chief executive Jeff Green compares to seaweed farming. After 30 to 60 days at sea, the fibres are brought ashore and the uranium eluted and purified into yellowcake, leaving no toxic tailings, before being sold into the existing supply chain like output from any conventional mine.
The economics are the real story. A national lab demonstration of the underlying chemistry extracted uranium at more than $200 a pound, over twice the price of Western mine supply, but Fluxnium says increasing the fibres’ surface area has pulled that cost down toward competitiveness. The timing follows a 75% rise in yellowcake prices over five years, per the U.S. Energy Information Administration, and a U.S. push to triple nuclear capacity by 2050 that depends on fuel the country mostly cannot mine domestically.
Green, previously a founder at Stamps.com and desalination company NanoH2O, is candid that none of the individual steps are novel; the work is entirely about driving cost out of a known process at scale. Fluxnium has not disclosed what its extraction cost is today, only where it started, so the gap between a national lab demonstration and a commercially competitive mine substitute remains Fluxnium’s to prove, not describe.
