Deploying nuclear reactors in mile-deep boreholes is significantly faster and cheaper than constructing traditional above-ground facilities.
The underground design provides an inherently superior safety profile by using the earth as containment and a water column as a passive cooling system.
The surging energy demand from data centers represents a primary and substantial market for new, small-scale nuclear power.
Nuclear power's current 20% share of US electricity is a baseline that will likely hold steady or increase, aided by new technologies like Deep Fission's.
Deep Fission is sufficiently funded with $100 million to reach its next major milestone, a commercial borehole proof-of-concept.
Pre-IPO
Liz Muller's company, Deep Fission, raised an initial $60 million in funding.
Recent
The company raised an additional $40 million through an IPO, bringing total funding to $100 million, which Muller states is sufficient for the next milestone.
Current
Muller states Deep Fission is actively building its first reactor in Parsons, Kansas, as part of the Department of Energy's Reactor Pilot Program.
Fall 2026
Muller announces the company's next major milestone is a planned commercial borehole proof of concept.
Late 2027 / Early 2028
Muller sets a target for Deep Fission's first reactor deployment and the commencement of supplying electricity to the grid.
▶Technological Disruption in Nuclear EnergyJun 2026
Muller champions Deep Fission's model of deploying pressurized water reactors in mile-deep boreholes as a paradigm shift. This approach drastically reduces construction time from years to weeks and lowers costs by eliminating complex above-ground structures like containment domes and pressurizers.
This focus on cost and speed directly addresses the primary historical barriers to new nuclear power development, potentially making it a more viable option for private investment and rapid deployment to meet rising energy demands.
▶Market Demand Driven by Digital InfrastructureJun 2026
Muller consistently highlights that over half of the 15 gigawatts of non-binding Letters of Intent for Deep Fission's reactors come from data center developers. This indicates a significant, emerging customer base that requires reliable, carbon-free, baseload power at scale.
By targeting the data center industry, Deep Fission is aligning itself with one of the fastest-growing sectors of the economy, potentially securing a foundational market that is less susceptible to the volatility of traditional utility energy procurement.
▶Strategic Execution and MilestonesJun 2026
Muller outlines a clear path forward for Deep Fission, detailing a total of $100 million raised to achieve a commercial borehole proof-of-concept in Fall 2026. The company is also building its first test reactor in Parsons, Kansas, with a target to supply grid power by late 2027 or early 2028.
Muller's emphasis on concrete, near-term milestones and sufficient funding provides a narrative of credibility and progress, crucial for building investor and customer confidence in a capital-intensive industry with long development cycles.
▶Inherent Safety by DesignJun 2026
Muller asserts that placing the reactor a mile underground provides an 'extraordinary' safety profile. The design leverages natural geological containment and uses a mile-long column of water for both pressurization and as a passive emergency core cooling system.
This reframing of safety from a complex engineering challenge to an inherent feature of the design could be a powerful tool for overcoming public and regulatory hurdles associated with nuclear power.