AI data centres are burning through electricity at a rate that should worry anyone paying attention to grid capacity. We’re looking at 945 TWh annually by 2030—that’s equivalent to the entire electricity consumption of Japan. And here’s the problem: you can’t power AI training and inference with solar panels and wind turbines alone, because AI needs baseload power running 24/7 without interruption.
This guide is part of our comprehensive analysis on how Big Tech is pivoting to nuclear power, where we explore the strategies behind this unprecedented energy shift.
So Microsoft, Amazon, and Google have each committed billions to nuclear power. But they’re not following the same playbook.
Microsoft is betting on speed—restarting Three Mile Island’s existing 837 MW reactor by 2028. Amazon is betting on scale, planning to build up to 12 new small modular reactors at their Cascade facility. Google is betting on innovation, partnering with Kairos Power for experimental molten salt reactor technology that’s never been commercially deployed.
These aren’t just different strategies. They’re different timelines, different costs, and different risks. If you’re running infrastructure on Azure, AWS, or Google Cloud, these nuclear bets will directly affect your pricing, your availability, and your company’s sustainability commitments.
How do Microsoft’s, Amazon’s, and Google’s nuclear strategies differ from each other?
Microsoft is prioritising speed. They’re restarting Three Mile Island’s existing reactor by 2028 for $1.6 billion. Amazon is prioritising scale through Multiple SMR modules eliminate single points of failure—12 X-energy reactors providing 320-960 MW at their Cascade facility in the early 2030s. Google is prioritising innovation with Kairos Power’s molten salt reactors targeting 500 MW by 2030-2035.
To understand the technology behind these investments, see our detailed explanation of SMR technology.
Microsoft’s strategy minimises regulatory delays by using existing infrastructure. Three Mile Island Unit 1 already has an NRC licence and proven technology. The restart avoids the decade-plus timelines you need for building new nuclear facilities from scratch. The downside? Microsoft now has single supplier dependency. If Constellation Energy hits problems, there’s no backup plan.
Amazon’s strategy provides redundancy. Multiple SMR modules eliminate single points of failure—the same way AWS designs availability zones. The partnership with Energy Northwest brings nuclear expertise and existing NRC relationships. X-energy’s TRISO fuel technology adds safety margins that traditional reactors can’t match. Learn more about this reactor technology in our detailed guide.
Google’s strategy carries the highest technical risk. Kairos Power’s molten salt reactors haven’t been commercially deployed anywhere in the world. The technology uses liquid fluoride salt as coolant, operating at temperatures up to 700°C compared to X-energy’s helium cooling and Constellation’s water cooling. Higher operating temperatures enable better efficiency and built-in energy storage without separate battery systems. This could provide demand flexibility that other designs can’t—if it works.
Timeline comparison tells the story. Microsoft targets 2028. Amazon’s first modules aim for early 2030s. Google’s reactors target 2030-2035, assuming no delays.
Cost structures vary accordingly. Microsoft’s restart runs approximately $1,900 per kilowatt. New SMR construction for Amazon will likely cost $6,000-$12,000 per kilowatt, reflecting the higher capital costs of factory fabrication facilities, modular manufacturing, and first-of-kind deployment risks. Google’s experimental technology carries unknown costs that probably exceed Amazon’s estimates, though specific figures remain undisclosed. For a comprehensive evaluation of these deployment costs, see our detailed financial analysis.
Each strategy aligns with how these companies think about infrastructure. Azure’s hybrid cloud strategy emphasises leveraging existing infrastructure. AWS’s redundancy culture demands multiple independent modules. Google’s moonshot investments tolerate higher-risk innovation.
Why did Microsoft choose Three Mile Island specifically?
Three Mile Island Unit 1 provides the fastest path to operational nuclear power. The reactor operated safely for 45 years until its 2019 shutdown for economic reasons, not safety concerns. It maintains its NRC operating licence. The existing infrastructure, cooling systems, and transmission lines reduce deployment time by 5-7 years compared to new construction.
Unit 1 was never involved in the 1979 incident. That accident affected only Unit 2, which was a completely separate reactor. This distinction matters for public perception and regulatory approvals.
Beyond its clean safety record, Three Mile Island’s location offers strategic advantages. The site in Pennsylvania provides grid access to Microsoft’s eastern US data centre cluster through the PJM interconnection. The 837 MW capacity matches the power requirements of a single large AI data centre, making the economics straightforward.
Microsoft’s 20-year power purchase agreement changes the economics entirely. Constellation plans to sell 100 percent of the electricity generated—enough to power 800,000 homes—exclusively to Microsoft.
The regulatory path is simpler than new construction. Restarting a dormant reactor requires less NRC review than certifying a new design. But the technical challenges include systems sitting dormant for years that need complete overhauls, and safety protocols must be updated to current standards.
Here’s the catch: no mothballed nuclear plant has ever been successfully restarted in United States history. Microsoft is attempting something that’s never been done before. The 2028 target is achievable in theory, but regulatory approvals and workforce recruitment could push that timeline.
The public perception challenge is real. Three Mile Island carries stigma from the 1979 accident, despite Unit 1’s clean record. Community engagement and safety reassurance messaging will determine whether local opposition creates delays.
What is Amazon’s Cascade project and how does it work?
Amazon’s Cascade Advanced Energy Facility is a partnership with Energy Northwest to deploy up to 12 X-energy Xe-100 SMRs near Richland, Washington. The facility provides 320-960 MW of scalable power for Amazon’s eastern Oregon data centre cluster.
The X-energy Xe-100 uses high-temperature gas reactors with TRISO fuel that physically cannot melt. Each module produces 80 MW. Amazon plans to start with 4 modules providing 320 MW, then scale to 12 based on demand and performance.
TRISO fuel consists of uranium particles coated in ceramic layers that remain stable even at temperatures exceeding 1,600°C. This eliminates meltdown risk and enables passive safety systems that cool the reactor for 7 days without external power or human intervention.
The location near Energy Northwest’s Columbia Generating Station makes sense. The site has existing nuclear infrastructure, Washington state has nuclear expertise, and community acceptance is higher than in areas without nuclear experience.
The phased deployment strategy mitigates risk. Individual reactor failures don’t compromise the entire facility. If early modules encounter problems, Amazon can pause deployment without losing all invested capital.
Manufacturing takes place at X-energy facilities using factory fabrication. Modules ship to the site for assembly, promising faster deployment than traditional on-site construction. The 24-36 month construction timeline per module beats the 5-10 years needed for traditional plants—assuming the factory production line operates as planned.
But factory fabrication requires sufficient orderbook to justify manufacturing investment. Amazon’s 12-reactor commitment provides that foundation, but X-energy needs additional customers to achieve economies of scale.
Industry consensus suggests first SMRs could come online around 2030. That assumes X-energy completes NRC design certification by 2027 (a process taking 22-41+ months minimum for new SMR designs), constructs manufacturing facilities, establishes supply chains, and ships the first modules on schedule. Historical nuclear projects suggest you should treat these timelines with healthy scepticism.
How does Google’s Kairos Power partnership differ from Microsoft’s and Amazon’s approaches?
Google signed an agreement to buy 500 megawatts of generating capacity from six to seven Hermes small modular reactors designed by Kairos Power, aiming to deploy by 2030. This represents the most advanced and unproven design among the three companies’ strategies.
The liquid salt transfers thermal energy to generate electricity and simultaneously serves as integrated thermal storage for demand management. This allows output variation for peak demand periods—a flexibility advantage over traditional baseload nuclear.
But no commercial molten salt reactor operates globally today. Moving from demonstration to commercial deployment faces a regulatory pathway less clear than proven designs.
Google’s involvement extends beyond customer relationship. The partnership structure includes Google in development, not just purchasing power after construction. This aligns with Google’s culture of technological experimentation and long-term research investments, similar to their quantum computing and other moonshot projects.
The Tennessee Valley Authority partnership provides nuclear expertise and regulatory navigation. TVA has decades of nuclear experience and established NRC relationships that could smooth the approval process.
The strategic risk differs from Microsoft’s and Amazon’s. Google is betting on a technological leap rather than incremental improvement. If Kairos technology succeeds, Google gains first-mover advantage with superior economics and operational flexibility. If it fails or encounters regulatory delays extending into the late 2030s, Google loses time and falls behind competitors whose more conservative bets pay off sooner.
Google is also pursuing a restart strategy with NextEra Energy at Iowa’s Duane Arnold nuclear plant (615 MW, 2029 target). This dual approach—restart for near-term power, Kairos for long-term innovation—hedges the technology risk.
What do these different nuclear strategies reveal about each company’s infrastructure philosophy?
Microsoft’s Three Mile Island restart reflects Azure’s hybrid cloud strategy. The approach prioritises leveraging existing infrastructure over building from scratch, paralleling how Azure supports Windows legacy systems and enterprise customer stability requirements. Speed matters more than cutting-edge technology.
Amazon’s multi-reactor Cascade approach mirrors AWS’s availability zone model. Multiple independent modules eliminate single points of failure, enabling redundant capacity that matches how AWS designs resilient infrastructure. The modular SMR deployment resembles incremental capacity expansion across regions.
Google’s Kairos innovation bet aligns with their culture of technological experimentation. The partnership structure and tolerance for higher-risk, longer-timeline technology development parallels their quantum computing research and other advanced projects. Innovation matters more than timeline certainty.
The four largest purchasers of corporate renewable energy—Amazon, Microsoft, Meta, and Google—have contracted over 50 GW of renewable power purchase agreements, equivalent to Sweden’s entire generation capacity. However, AI workloads are driving electricity demand growth that exceeds what renewable sources can reliably provide.
Mohammed Hassan, AWS senior technical program manager, explained their commitment: “We’re willing to put our money where our mouth is and invest in the development of these technologies because we know they’re going to be critical to meeting our sustainability targets.”
The timeline versus innovation trade-off defines the strategic differences. Microsoft optimises for speed, Amazon for reliability, Google for advancement. Azure customers get faster carbon-free power. AWS customers get more resilient infrastructure. Google Cloud customers fund experimental technology.
Risk allocation differs accordingly. Microsoft accepts single-supplier dependency to Constellation Energy. Amazon distributes risk across multiple modules and established SMR technology. Google accepts technology maturity risk betting on molten salt reactors.
What are the timeline risks for each company’s nuclear strategy?
Microsoft faces regulatory uncertainty around the Three Mile Island restart and the fact that no US facility has ever successfully completed this process. The 2028 target could slip due to environmental reviews, safety system upgrades, or workforce recruitment challenges. For a detailed understanding of the regulatory approvals required, see our regulatory roadmap analysis.
Amazon’s Cascade depends on X-energy completing NRC design certification by 2027, then scaling up manufacturing and establishing supply chains. A year ago, the first planned SMR in the United States was cancelled due to rising costs and lack of customers. The early 2030s timeline could easily slip to mid-2030s.
Google’s Kairos faces the longest regulatory pathway. First-of-kind molten salt reactor approval lacks operational precedent. The NRC takes a conservative approach to novel designs, and the certification process for advanced reactors stretches years into the future. Our analysis of NRC licensing requirements shows how complex this approval process can be. Commercial deployment could extend to the late 2030s.
Historical nuclear delays average 3-5 years. Cost overruns are typical. Regulatory surprises are common. The technical challenges vary by approach—systems sitting dormant for years need complete overhauls for restarts, while new SMR designs face manufacturing scale-up challenges and first-of-kind construction risks.
China’s Linglong One SMR demonstrates feasibility, but doesn’t reduce US regulatory timelines. The Nuclear Regulatory Commission has streamlined certain approval processes, but streamlined doesn’t mean fast.
What alternatives exist if nuclear projects fail to deliver on schedule? Companies maintain grid electricity and renewable energy contracts as backup power sources. Delayed nuclear deployment means continued reliance on carbon-intensive baseload power, jeopardising 2030 net-zero commitments. Alphabet’s demand response method allows reduced data centre power demand during grid stress by shifting computing tasks to alternative times and locations.
The competitive dynamics create pressure. The first company to operational nuclear power gains cost advantage, pricing power, and sustainability marketing benefits. Companies whose nuclear bets fail face competitive disadvantage against rivals whose projects succeed. Cloud pricing volatility increases if companies must purchase expensive grid power during peak AI demand. For businesses relying on these cloud platforms, delayed nuclear deployment creates direct operational consequences—potential pricing increases, availability constraints, and carbon accounting complications when their cloud provider’s nuclear strategy doesn’t deliver.
How do the cost structures compare across the three strategies?
Microsoft and Constellation Energy committed $1.6 billion to restart Three Mile Island Unit 1, providing 837 MW at approximately $1,900 per kilowatt. The 20-year power purchase agreement locks in long-term pricing.
New SMR construction for Amazon will cost significantly more. Industry estimates place new SMR construction at $6,000-$12,000 per kilowatt. For an in-depth cost and timeline analysis, see our detailed breakdown of deployment economics.
Google’s experimental Kairos technology carries unknown costs. First-of-kind development expenses, regulatory approval costs, and technology validation create a premium over established designs.
Restart economics favour Microsoft. Lower capital costs and existing infrastructure value enable faster return on investment. The facility already has grid connections, cooling systems, and transmission lines that new builds must construct from scratch.
Factory fabrication of SMRs promises economies of scale, but requires sufficient orderbook to justify manufacturing investment. Amazon’s 12-reactor commitment helps, but X-energy needs additional customers to drive costs down.
These cost structures matter even more when considering timeline risks, because delays multiply capital costs and extend the period before return on investment. Projects that come in on budget will still be more expensive than comparable gas or renewable projects. The federal government is contributing half of certain nuclear project costs, indicating that public subsidy is needed to make the economics work.
All three companies pass costs to cloud customers through infrastructure pricing. Initial investments of $1.6 billion to $10 billion or more will likely increase cloud pricing short-term. Long-term economics depend on whether nuclear provides cheaper power than grid electricity plus carbon offset costs.
Operational costs vary by design. Fuel costs, maintenance requirements, and staffing needs differ between restart operations, SMR modules, and experimental molten salt reactors. TRISO fuel for X-energy’s design costs more than traditional uranium fuel but offers safety advantages. Molten salt systems require specialised expertise that’s scarce.
Total cost of ownership includes construction, operations, decommissioning, and waste management across the lifecycle. SMRs produce less waste volume than traditional reactors but still generate spent fuel requiring disposal. Current US policy stores spent fuel on-site pending a permanent repository like Yucca Mountain or an alternative solution that remains politically contentious.
What happens if these nuclear projects fail to deliver on time?
AI workloads are driving electricity demand growth that exceeds what renewable sources can reliably provide. Data centres’ electricity consumption will more than double from 2024 to 2030, accounting for approximately 9 percent of total US electricity consumption.
Corporate sustainability pledges become unachievable. Reputation damage and investor pressure follow when net-zero commitments miss 2030 targets.
Natural gas is projected to continue supplying the largest share of energy at data centres through 2030, but nuclear could eventually play a larger role—if the projects deliver.
Recommended solutions include flexible power infrastructure implementing battery energy storage systems to enhance grid reliability, demand response programmes creating incentive structures for flexible electricity consumption patterns, and distributed generation accelerating on-site power production through natural gas facilities and rooftop solar installations deployable faster than utility-scale alternatives.
But these alternatives don’t solve the baseload power problem at the scale AI demands. Nuclear remains the only carbon-free source capable of providing 24/7 uninterrupted power at data centre scale—if the projects deliver on time and budget.
For a complete overview of how these nuclear strategies fit into the broader energy transformation for AI infrastructure, see our guide on nuclear-powered data centres.
FAQ Section
What is the difference between SMRs and traditional nuclear power plants?
SMRs produce 5-300 MW per module compared to traditional plants’ 1,000+ MW output. They use factory fabrication for faster deployment taking 24-36 months versus 5-10 years for traditional construction. They incorporate passive safety systems that cool reactors for 7 days or more without external power or human intervention.
Is Three Mile Island safe to restart after the 1979 accident?
Unit 1 shut down in 2019 for economic reasons, not safety concerns. It maintains its NRC operating licence with a clean safety record throughout its 45-year operational history.
When will these nuclear-powered data centres actually be operational?
Microsoft targets 2028 for Three Mile Island restart. Amazon’s first Cascade modules aim for early 2030s. Google’s Kairos reactors target 2030-2035. Historical nuclear delays suggest 3-5 year slips are possible.
Why not just use solar and wind power for AI data centres?
AI training and inference require 24/7 uninterrupted baseload power. Solar and wind are intermittent sources. Battery storage at data centre scale remains prohibitively expensive and technically challenging.
Will nuclear-powered data centres make cloud computing more expensive?
Initial infrastructure investments will likely increase cloud pricing short-term. Long-term economics depend on whether nuclear provides cheaper power than grid electricity plus carbon offset costs.
What is TRISO fuel and why does Amazon’s X-energy use it?
TRISO fuel consists of uranium particles coated in ceramic layers that physically cannot melt even at temperatures exceeding 1,600°C. This eliminates meltdown risk and enables passive safety systems.
How does molten salt cooling in Google’s Kairos reactors work?
Molten fluoride salt absorbs heat from the reactor core at temperatures up to 700°C. It transfers thermal energy to generate electricity while serving as integrated thermal storage for demand management.
What regulatory approvals do these projects need?
New SMR designs require NRC design certification taking 22-41+ months minimum for new designs. They need construction permits, environmental reviews, and state regulatory approvals. Three Mile Island restart needs fewer approvals due to its existing licence.
Can these nuclear projects meet tech companies’ 2030 net-zero commitments?
Only Microsoft’s 2028 Three Mile Island restart might contribute to 2030 goals. Amazon’s and Google’s projects target early-to-mid 2030s, after most net-zero deadlines.
What happens to nuclear waste from these SMRs?
SMRs produce less waste volume than traditional reactors but still generate spent fuel requiring disposal. Current US policy stores spent fuel on-site pending a permanent repository.
Why are Meta and Oracle pursuing nuclear power for AI?
Meta released a request for proposals to identify nuclear energy developers, though specific projects haven’t been announced. Oracle revealed plans for a three-SMR data centre larger than 1 GW, but details remain limited.
How much energy does AI really consume compared to traditional computing?
A single ChatGPT query consumes approximately 10 times more energy than a Google search. AI data centres require 100-200 kilowatts per rack compared to 5-10 kilowatts for traditional servers.
