Fluxnium has emerged from stealth with $7 million in seed funding and a plan to extract uranium directly from seawater, potentially opening a vast new source of nuclear fuel if the startup can make a decades-old scientific concept economically competitive.
NOTE : Congruent Ventures led the round, with Active Impact Investments and US nuclear operator Constellation Energy participating.
Fluxnium is developing technology based on chemistry licensed from the US Department of Energy and research conducted at national laboratories. The approach exploits the roughly 4 to 5 billion metric tons of uranium naturally dissolved in the world’s oceans. At today’s global reactor requirements of roughly 69,000 tons per year, that theoretical inventory corresponds to tens of thousands of years of current consumption. It should not, however, be confused with an economically recoverable reserve.
Uranium occurs in seawater at only about 3.3 parts per billion, making extraction extremely difficult. Fluxnium uses specially engineered polymer fibers that preferentially bind dissolved uranium. Long braided sections would be suspended from offshore buoys for 30 to 60 days, recovered and processed to remove the captured material, then reused several times. The uranium would ultimately be purified into yellowcake for the conventional nuclear-fuel supply chain.
Similar amidoxime-based adsorbents have been studied for decades. The obstacle has consistently been cost. Previous US laboratory work produced uranium at estimates above $200 per pound, well above conventional mining. Fluxnium says it has increased the fibers’ surface area and improved their manufacturing and deployment enough to approach competitiveness with mined uranium. That claim has not yet been demonstrated at commercial scale.
The opportunity is growing as nuclear expansion increases pressure on fuel supplies. But Fluxnium’s breakthrough will depend less on proving that seawater contains uranium (that is well established) than on showing it can recover meaningful quantities cheaply, repeatedly and at industrial scale.