Nuclear Startups Court Cold War Plutonium as AI Power Demand Drives Capital Into the Sector

Nuclear Startups Court Cold War Plutonium as AI Power Demand Drives Capital Into the Sector Reactor developers are in advanced talks to buy decommissioned weapons-grade material, a supply workaround surfacing just as money rotates hard into nuclear-linked equities. Capital is rotating into companies that can feed AI data centers, and nuclear baseload is one of the cleanest answers traders are buying. Fluence Energy closed at $24.16 on May 8 (2026-05-08), up 98.2% in a single week, after disclosing master supply agreements with two hyperscalers and a record $5.6 billion backlog.¹ That matters because the same demand pull now reaching grid-storage names is what nuclear startups are betting on, and they need fuel. The clearest sign of how far developers will reach for it: reactor companies are in advanced negotiations to buy plutonium left over from Cold War weapons programmes, repurposing material that spent decades as a strategic liability into reactor feedstock.⁷ It is an unusual supply route, and it tells you something about the bottleneck. Uranium, not capital, is the constraint the market is pricing. Citi analysts expect uranium to climb as high as $125 per pound this year as renewed interest in nuclear drives demand past available supply, according to coverage of the sector.⁵ The equity move has been violent in both directions. Nuclear stocks sold off sharply before recovering, with some names up over 100% year-to-date after what looked in hindsight like a buying opportunity around the DeepSeek scare, TheStreet Pro reported.⁶ Investors keep treating the sector as a direct play on AI electricity demand, and the volatility reflects how thin the fundamental anchors still are.⁶ Fluence itself is a reminder that the rotation is not uniformly kind. Shares are down roughly 39% year-to-date, leaving the company in turnaround territory despite the one-week surge.¹ It posted positive adjusted EBITDA of $2.0 million in the first quarter of 2026, a fourth consecutive quarter in the black, with non-GAAP gross margin widening to 52%.¹ Chief executive Arun Narayanan said the operational discipline and margin profile established in 2025 "are proving durable."¹ The pull-through to physical fuel suppliers is where the more durable case sits. Analysts expect Cameco's revenue and adjusted EBITDA to grow at compound annual rates of 8% and 12% respectively between 2025 and 2028, a forecast built on the same demand thesis driving the plutonium hunt.⁵ If reactor builders are willing to negotiate for decommissioned weapons material, the implication is that conventional supply chains are not expected to keep pace. Set against the hype, the gas market offers a sober counterpoint on what AI demand has not yet done. US working gas in storage fell by 52 billion cubic feet for the week, well below the five-year average withdrawal of 168 Bcf, EIA data cited by Nasdaq showed.² Inventories now sit 141 Bcf above a year earlier, roughly 8% higher.³ Henry Hub front-month gas briefly dipped toward $2.75/MMBtu before rebounding on short-term cold forecasts, closing around $2.86 on NYMEX.³ That gap is the trade tension worth holding in mind. Nuclear equities are priced for a structural demand surge that the physical gas curve, sitting below $3, has not begun to reflect. One market is discounting a future of insatiable AI power draw; the other is still trading a comfortable supply cushion. Both cannot be fully right on the timeline. Europe's gas complex is moving on its own drivers, unconnected to the AI story. EU gas rose 2% on Thursday (2026-05-21) after Iran said it was not prepared to negotiate despite a US peace proposal, with forecast cold weather adding support.⁴ ICE Endex TTF front-month initially climbed to EUR 54.17/MWh, with front-month prices described as volatile on mixed Iran-US signals, Montel reported.⁴ The signal to watch is whether the plutonium negotiations produce an actual transaction. Advanced talks are not a deal, and weapons-grade material carries regulatory and proliferation hurdles that storage agreements and supply contracts do not.⁷ Until one closes, the cleaner read on conviction is uranium itself. A move toward Citi's $125 target would confirm the supply squeeze the startups are scrambling to get ahead of.⁵ For now the divergence is the story. Money is paying up for nuclear's promise while the fuel to deliver it remains contested enough that decades-old bomb material is on the table. Watch the spot uranium print and watch whether any plutonium purchase moves from negotiation to signature.