Westinghouse Signs $80bn US Government Nuclear Deal as Japan Readies Kashiwazaki-Kariwa Restart
AI-driven power demand is turning nuclear from a stranded asset into an infrastructure bet, but cost economics remain unfavourable and Japan's restart timeline keeps slipping.
Westinghouse, the nuclear engineering firm 49% owned by Cameco, became part of an $80 billion agreement with the US government on May 21 (2026-05-21) to build new reactors for artificial intelligence data centre deployment — the most concrete financial commitment yet to nuclear as the primary power supply for the technology industry's next growth phase.1
That agreement arrived as Japan's Kashiwazaki-Kariwa nuclear plant, the largest in the world, remained on standby for restart after years of safety reviews and regulatory delays. The gap between an American industry moving toward large-scale procurement and a Japanese grid still cautiously reopening individual plants captures the divergent pace at which the global nuclear revival is advancing.3
Japan's energy trajectory has been shaped by two overlapping shocks. The Fukushima disaster in 2011 shut down a nuclear fleet that had by 2010 grown to 54 operational reactors, supplying roughly 25% of the country's electricity and angled toward 50% by 2030.3 The Iran conflict and the effective closure of the Strait of Hormuz delivered the second shock: approximately 90% of Japan's crude oil arrives from the Middle East, and Tokyo responded to the supply pressure by releasing around 80 million barrels from its strategic petroleum reserves, the equivalent of about 26 days of domestic oil demand.2
The short-term response went further. Japan and South Korea ramped coal-fired power generation from April through early May (2026-05-01 to 2026-05-09) after LNG supplies tightened and Asian spot prices climbed, according to IDNFinancials.5 JKM Asian LNG front-month stood at $15.52 on Monday (2026-06-29). Coal's return as emergency supply is a direct consequence of the gap left by a nuclear fleet that has been only partially reactivated in the fifteen years since Fukushima.
Japan's latest energy plan targets renewables at 40 to 50% of electricity generation by 2040, up from around 25% as of 2025, with nuclear retained as a complement. Researchers from the Lawrence Berkeley National Laboratory estimate renewables could reliably generate 70% of Japan's electricity — a figure the government has not formally adopted as a target.3 Kashiwazaki-Kariwa's restart would represent the most significant single step toward reducing Japan's exposure to fossil fuel import disruptions, but local opposition and the accumulated weight of post-Fukushima regulatory requirements have stretched the process well beyond initial timelines.
The United States is setting more ambitious objectives. The government has targeted quadrupling nuclear capacity from approximately 100 gigawatts in 2024 to 400 gigawatts by 2050, according to finance.yahoo.com.1 Bank of America estimates the nuclear market opportunity at $10 trillion. The World Nuclear Association projects uranium demand rising 28% by 2030 and more than doubling by 2040.1
Small modular reactors are absorbing most of the private capital. SMR startups have raised more than $2 billion since early 2024, with Goldman Sachs now incorporating SMRs into its power-sector forecasts, according to capwolf.com.4,6 Joe Dominguez, chief executive of Constellation Energy, estimates that incremental improvements to existing US plants could add 7 to 10 gigawatts of capacity, and that big tech's funding commitments could make 30 gigawatts available that would not otherwise reach the market.4
Artificial intelligence is now embedded in reactor design as well. Idaho National Laboratory and Nvidia launched a collaboration in early 2026 aimed at cutting reactor build times by up to 50% and reducing operating costs by a similar margin, under a project called Prometheus.7 The stated targets are ambitious and unproven at commercial scale, but the direction is consistent with a broader pattern: the same data-centre operators driving power demand are also funding the supply response.
The cost obstacle has not been resolved. Barclays noted that both conventional nuclear and SMR costs still exceed the market price for power, a constraint that persisted despite the fundraising surge.4 On the supply side, Cameco produced about 17% of the world's uranium in 2024, second only to Kazakhstan's Kazatomprom at 21%, with Orano at 11%.1 The uranium ETF URA was at $43.59 on Monday (2026-06-29), down 0.7% on the session.
The near-term test is in Japan rather than Washington. Whether Kashiwazaki-Kariwa's restart accelerates into a broader programme of reactor activations, or remains a single case managed on its own regulatory merits, will determine how quickly the world's third-largest economy reduces structural reliance on Middle Eastern crude and Asian LNG spot markets where price volatility is now driven by geopolitical risk as much as by supply fundamentals.3