Fluxnium has emerged from stealth with a seawater uranium-extraction system as the U.S. seeks to triple nuclear power capacity by 2050. Yellowcake prices have risen 75% over five years, while uranium supplies are concentrated among a small group of countries, creating geopolitical concerns. The company uses polymer fibers that attract dissolved uranium, deploying them from buoys for 30 to 60 days before bringing them ashore for extraction and processing into yellowcake. Fluxnium recently raised $7 million in seed funding led by Congruent Ventures, with participation from Active Impact Investments and Constellation Energy.