Nuclear startup Deep Fission has slipped onto the public markets through a reverse merger that raised roughly $30 million, a modest haul for a capital-intensive industry and a structure that raises as many questions as it answers. The deal was priced at $3 per share—well below the $10 level that traditional SPACs target—and the company says it intends to quote on the OTCQB, a venue known more for early-stage exposure than deep liquidity.
Deep Fission’s pitch is as unconventional as its listing. The company proposes compact, pressurized-water reactors rated at 15 megawatts each, packaged in cylindrical modules designed to be lowered into 30-inch boreholes drilled about a mile into the ground. By burying the reactor and much of its balance-of-plant, the company argues it can tamp down security risks, simplify siting, and reduce the consequences of worst-case accidents.
A low-price SPAC with high stakes
Reverse mergers are hardly novel in climate tech, but the pricing here is unusual. SPACs typically list units at $10, then fight off redemptions as they close. Coming public at $3 suggests Deep Fission prioritized certainty of capital over optics, and likely lacked a sizable PIPE to backstop the deal. Listing on the OTCQB trims listing friction but also narrows the potential investor base and heightens volatility.
That $30 million buys time, not victory. First-of-a-kind nuclear projects routinely require hundreds of millions just to reach a licensed, grid-capable prototype. Recent market history is sobering: one small modular reactor developer terminated a flagship project after projected costs escalated, and another advanced reactor company that pursued a SPAC saw heavy redemptions before pivoting. The lesson is consistent—nuclear hardware rewards deep balance sheets and disciplined execution.
The compliance costs that come with being public add pressure. SEC reporting, internal controls, and investor relations can consume a meaningful slice of a startup’s operating budget, especially when core engineering and licensing work are just beginning to ramp.
Burying reactors to de-risk operations
Deep Fission’s underground approach courts a different kind of risk-reward. Using pressurized water aligns the design with a technology lineage proven in naval propulsion and commercial power, where the International Atomic Energy Agency and U.S. Energy Information Administration have documented world-leading capacity factors. The innovation is siting: a deep, narrow shaft intended to put thick rock between the core and the surface.
If it works, underground placement could shrink the security perimeter, limit exposure to external hazards, and offer passive heat rejection to surrounding geology. But the engineering challenges are nontrivial. Hydrogeology, corrosion, maintenance access, refueling logistics, and spent-fuel retrieval all require rigorous solutions. The U.S. Nuclear Regulatory Commission has flagged many of these issues in advanced reactor pre-application engagements, and will expect hard evidence that the subsurface environment is a safety asset rather than a complication.
Deep siting has precedents in nuclear waste programs—Finland’s Onkalo repository is the most cited example—yet deploying an operating power reactor underground is a different proposition. The company’s reliance on low-enriched uranium typical of pressurized-water systems could simplify fuel supply compared with designs that require high-assay fuel, a practical edge amid ongoing HALEU scarcity.
Data centers as anchor load
Deep Fission has aligned early with data center developer Endeavor on a plan for up to 2 gigawatts of capacity. On paper, that’s on the order of 130 units of the company’s 15-megawatt modules. The pitch resonates: hyperscale and AI workloads are ravenous for round-the-clock power, interconnection queues are clogged, and many grids are short on firm, carbon-free supply.
Analysts at the International Energy Agency and grid operators have warned that data center demand is accelerating faster than new firm generation. A colocated “micro-nuke” campus could offer a self-contained solution that bypasses long lead times for transmission upgrades while delivering high capacity factors. The flip side is customer concentration risk and the need to prove ultra-high reliability from day one; a data center will not tolerate teething issues in a first-of-kind plant.
Economically, the bar is high. Levelized cost remains the acid test. While some investment banks and consultancies have modeled competitive costs for modular reactors at scale, the cost curve only bends after a repeatable manufacturing cadence is established. Without it, per-unit economics can drift upward rather than down.
Regulatory and financing runway
Deep Fission was named to the Department of Energy’s Reactor Pilot Program, a signal that the company may benefit from a clearer permitting pathway and early federal engagement. That complements ongoing NRC efforts to modernize advanced reactor licensing frameworks. Even so, milestones—site selection, environmental review, safety analysis reports, and fuel qualification—will dictate timelines more than capital markets will.
On the finance side, the company will likely need a multi-pronged stack: customer prepayments or offtakes, government cost sharing, strategic equity, and eventually project finance. Technology-neutral clean power credits created under recent federal policy could improve project returns, particularly if coupled with domestic content and workforce incentives, but those benefits still require a licensed, operating plant to monetize.
What to watch next
Key tells will arrive quickly: final SPAC redemption and cash balance disclosures, confirmation of an OTCQB quote and trading liquidity, and indications of a near-term licensing strategy with the NRC. On the engineering front, expect proofs around drilling at scale, underground containment design, passive safety systems, and maintainability.
If Deep Fission can demonstrate that a buried, pressurized-water microreactor is practical and economical, it will have reframed nuclear siting and security for a new class of customers. If not, this SPAC may be remembered as another experiment in nuclear finance rather than a breakthrough in nuclear deployment.