Molten Salt Solutions has closed an oversubscribed $7 million seed round to advance from laboratory validation to pilot-scale production of lithium-6 and lithium-7 — two isotopes without which a large share of next-generation reactors, both fusion and molten salt, simply cannot operate. The funding brings total capital raised by the Santa Fe, New Mexico-based company to $10 million.
The round was led by Dolby Family Ventures, with participation from Vanedge Capital Partners, Alumni Ventures, Gaingels, True Ventures, and Future Ventures. The latter has an established focus on advanced energy, with positions across next-generation nuclear, fusion, and critical materials. The makeup of this investor coalition signals how nuclear supply chain security is increasingly becoming a priority for U.S. private capital.
The two isotopes serve distinct purposes. Lithium-6 is essential for fusion systems: when it interacts with neutrons, it produces the tritium needed to sustain thermonuclear reactions. Lithium-7, on the other hand, is used in advanced fission reactors — particularly molten salt configurations — where it reduces neutron absorption and limits unwanted tritium generation during operation. The applications differ, but the underlying problem is the same: the United States currently has no domestic commercial production of either isotope. In a climate of intensifying geopolitical competition over energy technologies, that dependence on foreign suppliers represents a genuine strategic vulnerability.
MSS’s platform relies on a proprietary solvent exchange process that consolidates multiple separation stages into a single integrated system, rather than distributing them across thousands of discrete steps as conventional methods require. The company claims efficiency levels one hundred times greater than traditional approaches — a figure that, if validated at pilot scale, would fundamentally reshape the economics of enriched isotope production. The new funds will be used to expand technical and operational teams, fulfill existing customer agreements, and develop a broader isotope portfolio targeting emerging technology markets.
The broader industry backdrop is favorable. Global nuclear capacity is projected to more than double by 2050, approaching 1,000 gigawatts according to International Atomic Energy Agency estimates. Molten salt reactors such as those developed by Fissionaire — with which MSS already has supply agreements — and fusion systems like those of Type One Energy and Gauss Fusion will depend on enriched lithium supplies that currently do not exist at adequate scale. Molten Salt Solutions occupies precisely this gap: between reactor technology, which has attracted considerable attention and investment, and the materials those reactors actually require to function — materials that have remained in the background for decades. If the transition to pilot scale proceeds on schedule, MSS could establish itself as a strategic supplier for a supply chain that the U.S. nuclear industry urgently needs to build before its next-generation reactors are ready to come online.
