Marathon Fusion

About Marathon Fusion

Positioned at the intersection of advanced materials science and clean energy, Marathon Fusion is a San Francisco-based company founded in 2023. The firm was established by CEO Kyle Schiller, a former science policy fellow at Schmidt Futures, and CTO Adam Rutkowski, whose background includes roles as a Propulsion Engineer at SpaceX and a PhD candidate in Plasma Physics at Princeton University. Marathon Fusion is focused on developing critical fuel cycle technologies to enhance the economic viability and accelerate the deployment of commercial fusion power plants.

The company's core business revolves around creating enabling technologies for the broader fusion industry. Its primary product is a high-throughput fuel processing system designed to efficiently recycle fusion fuel, specifically deuterium and tritium. This is achieved through the development of advanced metal foil pumps that leverage a principle known as hydrogen superpermeation, allowing for the rapid and continuous recycling of the fuel. A key benefit of this technology is its ability to reduce the amount of tritium inventory required for a power plant to operate, which in turn can lower operational expenses and enable the construction of smaller, more economical facilities. The company has secured Letters of Intent with leading private fusion developers, including Commonwealth Fusion Systems and Helion Energy, to supply these fuel systems.

Recently, Marathon Fusion announced a significant development that could alter the economic model of fusion energy. The company has detailed a method for scalable nuclear transmutation, specifically turning the mercury-198 isotope into gold-197. By introducing mercury into the fusion process, the high-energy neutrons produced can trigger a reaction that results in mercury-197, which subsequently decays into stable gold. According to the company's modeling, this process could yield as much as five metric tons of gold per year for each gigawatt of electricity generated, potentially doubling a fusion plant's revenue streams without compromising power output. This approach aims to address one of the main hurdles for fusion energy: the immense capital cost of reactor construction. Beyond gold, the technology may have applications in producing other valuable materials, such as medical isotopes.

Marathon Fusion has attracted considerable financial backing, securing a total of $10.9 million through a combination of venture capital and government grants. Its funding includes a $5.9 million seed round led by 1517 Fund and Anglo American, as well as support from the Breakthrough Energy Fellows program, the Department of Energy's ARPA-E, and other investors.