Energy is the cornerstone of modern life. We need electricity for healthcare, transportation, communication, and more. Many countries are choosing nuclear power because it offers a lot of electricity and produces no direct carbon dioxide emissions. However, building traditional nuclear plants is costly. They can take a long time to set up, and people often doubt their safety.
Small Modular Reactors (SMRs) offer a potential way forward. SMRs aim to deliver safe, reliable, and clean electricity. They do this by shrinking reactor size and standardizing construction. This approach reduces the risks and costs tied to traditional nuclear plants.
If you’re looking for a one-stop resource on SMRs—complete with technical details, key players, regulatory considerations, and future trends—this guide is for you.
Table of Contents
- 1. What is a Small Modular Reactor?
- 2. How Is Nuclear Power Shaping Global Energy Consumption?
- 3. Nuclear as a Cleaner and Safer Energy Source
- 4. What Does the Future Hold for Nuclear Energy?
- 5. How Do SMRs Work?
- 6. Advantages of SMRs
- 7. Regulatory & Permit Process for SMRs
- 8. Challenges Facing SMRs
- 9. Leading SMR Projects and Technologies Under Construction
- 10. SMRs and Big Tech Companies: The Future of Data Centers and AI
- 11. SMRs and Carbon Credits
- 12. The Future of SMRs
- 13. Conclusion
- 14. Key Takeaways
What is a Small Modular Reactor?
A Small Modular Reactor is a nuclear reactor with an electric output of up to 300 megawatts (MWe) per unit. Unlike traditional reactors that exceed 1,000 MWe, engineers design SMRs as modular systems, factory-building components for faster assembly. This method can cut down on construction time and costs, all while keeping safety standards high.
The International Atomic Energy Agency (IAEA) says that SMRs are promising. They can fit into different power grids, provide both electricity and heat, and serve countries with smaller energy needs. They also appeal to developed nations seeking to replace aging reactors or achieve net-zero targets with minimal risk.
Why Are SMRs Important?
With global warming on the rise, many nations must find ways to supply affordable, low-carbon electricity. Large nuclear plants can take well over a decade to build, cost billions of dollars, and face social and political challenges. SMRs, on the other hand, promise:
- Faster Deployment: Factory assembly can shorten construction timelines.
- Lower Financial Risk: Smaller plants mean smaller capital outlays and potentially lower financing costs.
- Flexibility: SMRs can serve remote areas, industrial sites, or developing regions without robust grids.
In short, SMRs bridge the gap between large nuclear plants and renewable energy, offering steady, carbon-free power that can support solar and wind during periods of low sunlight or wind.
But before we dive into the SMR details, it helps to have a broader picture of the nuclear energy landscape and know the trends that led to the rise of SMRs.
How Is Nuclear Power Shaping Global Energy Consumption?
Nuclear energy has been a critical part of the world’s power supply for decades. Today, it provides about 10% of global electricity, with over 400 reactors operating in more than 30 countries.
Countries Leading in SMR Development and Deployment
The U.S. (with 22 designs), Russia (17), China (10), Canada (5), and the UK (4) lead SMR development and deployment. They have significant investments and government-backed projects. Over 80 SMR designs are currently under development in 18 countries.
Some countries, such as France, depend on nuclear power for over 70% of their electricity. The United States and China are also increasing their nuclear capacity. They want to rely less on fossil fuels.

Compared to fossil fuel plants, nuclear power plants operate at a higher capacity factor. This means they produce electricity more efficiently and consistently.
While coal and natural gas plants may run at about 50–60% capacity, nuclear plants often reach 90% or higher. This makes nuclear energy one of the most reliable sources of electricity in the world.
Growth in Nuclear Power Use
As the world shifts toward cleaner energy, nuclear power is becoming more important. In 2023, nuclear power plants worldwide generated around 2,600 terawatt-hours (TWh) of electricity.
The demand for electricity continues to rise, and countries are prioritizing nuclear energy as a reliable solution. Countries such as the USA and China are leading nuclear expansion efforts, with multiple reactors under construction.
Top Countries by Nuclear Energy Supply and Consumption in 2023

Source: International Atomic Energy Agency
Some countries are rethinking their nuclear investments. Germany, for example, closed its last nuclear plants in 2023. But now, rising energy costs and supply worries have sparked talks about restarting nuclear programs.
Global SMR Tracker: Monitoring Small Modular Reactor Development
For stakeholders tracking the rapid evolution of small modular reactors, the World Nuclear Association’s SMR Global Tracker serves as the definitive resource for real-time insights. Updated in January 2025, this tool provides:
- Comprehensive Coverage: 80+ SMR designs across 18 countries, including the U.S., China, Russia, and Canada.
- Development Stages: Filters for conceptual, licensed, and operational projects (e.g., NuScale’s Idaho pilot, Russia’s RITM-200M deployments).
- Technical Specifications: Reactor type (PWR, molten salt, gas-cooled), capacity (1–300 MWe), and coolant systems.
- Market Trends: Growth metrics like the 120 GW global SMR capacity target by 2050 under IEA’s net-zero scenarios.

Nuclear as a Cleaner and Safer Energy Source
One of the biggest advantages of nuclear power is that it is a low-carbon energy source. Unlike coal and natural gas, nuclear reactors do not produce greenhouse gas emissions during operation.
According to the International Energy Agency (IEA), nuclear energy prevents over 2 billion metric tons of CO2 emissions annually. This makes nuclear power an essential tool in the fight against climate change.
Carbon Emissions Comparison
Compared to fossil fuels, nuclear energy has a much lower carbon footprint. The lifecycle emissions of nuclear power—accounting for mining, fuel processing, construction, and decommissioning—are estimated at about 12 grams of CO₂ per kilowatt-hour (gCO₂/kWh). In contrast:
- Coal: Around 820 gCO₂/kWh
- Natural gas: Around 490 gCO₂/kWh
- Solar: Between 40-50 gCO₂/kWh (mainly from production)
- Wind: Around 10-12 gCO₂/kWh

Source: World Nuclear Association
Safety Improvements
Nuclear energy often gets a bad rap for its perceived dangers. However, statistics reveal a different story: it’s one of the safest energy sources around! According to the World Health Organization (WHO), nuclear power results in fewer deaths per energy unit than coal, oil, or biomass. The numbers paint a picture of safety that defies common belief.
In particular, coal mining results in thousands of deaths each year due to lung diseases, explosions, and accidents. In contrast, nuclear energy has caused fewer fatalities. This makes it a much safer option for energy production.
Modern nuclear reactors include many safety features. They have passive cooling systems and automated shutdown mechanisms to prevent accidents. Past nuclear incidents like Chernobyl and Fukushima drove regulators to mandate safer reactor designs.

How SMRs Compare to Renewables in Cost and Reliability
SMRs provide consistent, 24/7 baseload power, unlike solar and wind, which depend on weather conditions. Solar and wind energy can be cheaper, costing $20–$50/MWh. However, SMRs provide long-term reliability. This makes them great for stabilizing the grid.
But, the cost-effectiveness and feasibility of SMRs are still unclear. Initial estimates show they might cost more than regular reactors.
What Does the Future Hold for Nuclear Energy?
The future of nuclear energy looks strong. Many governments view this as a way to tackle climate change and ensure energy security. Currently, around 80 reactors are being built globally.
The IEA predicts that nuclear capacity will need to double by 2050 to meet global climate goals. The World Nuclear Association says nuclear capacity could hit 800 gigawatts (GW) worldwide by 2050. That’s double the roughly 400 GW we have today.
Several countries are investing heavily in nuclear energy:
- China plans to add 150 new reactors by 2050.
- India aims to increase its nuclear capacity from 7 gigawatts (GW) to 22 GW by 2031.
- United States is supporting advanced nuclear projects and extending the lifespan of existing reactors.
- Russia proposes constructing 34 new nuclear reactors by 2042, aiming to add about 28 GW.
Investment in Nuclear Technologies
The U.S. Department of Energy (DOE) is putting in $3.2 billion. This money will help create next-generation reactors, such as SMRs and Advanced Nuclear Reactors (ANRs). Of this, $1.2 billion will fund the Advanced Reactor Demonstration Program (ARDP). This program aims to have two fully operational advanced reactors by the late 2020s.
One major beneficiary is TerraPower, a Bill Gates-backed company. It received $2 billion in funding for its Natrium reactor project in Wyoming. This project features a 345-megawatt (MW) sodium-cooled fast reactor. It could increase output to 500 MW when paired with its thermal energy storage system.
Outside the U.S., countries like Canada and the UK are also ramping up investments.
Canada’s Strategic Innovation Fund will invest $970 million in Ontario Power Generation’s SMR project. Meanwhile, the UK government has committed £1.7 billion ($2.1 billion) to Rolls-Royce for SMR development.
These investments show a strong belief in nuclear technology. It will be an important part of future energy systems.
Notably, global investment in nuclear energy is set to rise. Right now, it’s about $65 billion each year. By 2030, it could hit $70 billion with current policies. Nuclear capacity is expected to grow by over 50% to nearly 650 GW by 2050.

With stronger government actions, investment could go even higher. In the Announced Pledges Scenario (APS), if we fully apply energy and climate policies, investment may hit $120 billion by 2030. Also, nuclear capacity would more than double by mid-century.
In the Net Zero Emissions by 2050 scenario, investment might top $150 billion by 2030. Capacity could exceed 1,000 GW by 2050.
Large reactors lead the way in investment. However, Small Modular Reactors (SMRs) are growing fast. Under APS, over 1,000 SMRs will be deployed by 2050, with a total capacity of 120 GW. Investment in SMRs will jump from $5 billion today to $25 billion by 2030.
Investment Trends: The Case for SMRs
Cost-competitive small modular reactors could change the nuclear energy scene. Government support and new business models back this shift. There’s strong interest in SMRs due to the need for reliable, clean power, especially from data centers. Current plans aim for up to 25 GW of SMR capacity, with hopes for 40 GW by 2050 under current policies.
With better policy support and simpler regulations, SMR capacity could reach 120 GW by mid-century. This would need more than 1,000 SMRs. This growth would need a big investment jump from $5 billion today to $25 billion by 2030, totaling $670 billion by 2050.
If SMR construction costs drop to match large reactors in 15 years, capacity might hit 190 GW by 2050. This could spark $900 billion in global investment.

SMRs, along with efficient large-scale reactors, can help Europe, the US, and Japan lead in nuclear technology again. By 2050, nuclear capacity in advanced economies might grow by over 40%, aiding energy security and emissions targets.
So, what exactly are these SMRs and why are they changing the future of the nuclear energy landscape?
- Click here for live URANIUM prices.
How Do SMRs Work?
Nuclear reactors produce heat by nuclear fission. As it is shown in the following image, uranium fuel undergoes a chain reaction where uranium atoms split, releasing energy in the form of heat and neutrons. Water or another coolant absorbs this heat and turns it into steam. The steam then drives a turbine connected to a generator, producing electricity.

Modular Construction
The distinctive feature of SMRs is their modular design. Companies create key parts such as reactor vessels, steam generators, and control systems in specialized factories. Then, these modules are shipped to the installation site. Workers assemble them like Lego blocks.
This approach offers several advantages:
- Quality Control: Factory settings can adhere to strict standards, reducing on-site errors.
- Faster Assembly: On-site construction primarily involves connecting pre-built modules, speeding up timelines.
- Scalability: Utilities can start with one module and add more as energy demand grows.

Advanced Safety Features
Most small modular reactors rely on passive safety systems. This means they can shut down or cool themselves without relying on human intervention or external power:
- Gravity-Driven Coolant: If the reactor overheats, gravity pulls cool water into the core.
- Smaller Cores: Less radioactive material means lower risk in worst-case scenarios.
- Underground or Submerged Designs: Placing reactors below ground adds a natural barrier against external hazards.
Such features not only lower the probability of a major incident but also help ease public concerns about nuclear safety.
Fuel Variants
While most SMRs use low-enriched uranium (LEU) at about 3-5% enrichment, some advanced designs plan for high-assay low-enriched uranium (HALEU) (up to 20% enrichment) or molten salt fuel for enhanced efficiency.
A handful of cutting-edge concepts even explore thorium or gas-cooled reactors, aiming to reduce radioactive waste and improve thermal performance.
How SMRs Tackle Nuclear Waste Disposal
SMRs create less waste. They might also use advanced fuel cycles. For example, they can recycle spent fuel or use molten salt reactors that can cut down long-term storage needs. These innovations aim to minimize environmental impact.
Advantages of SMRs
As already mentioned earlier, small modular reactors offer a lot of benefits that make them attractive to both developers and investors alike. Here are the major advantages this nuclear technology provides:
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Lower Carbon Footprint
Nuclear reactors produce electricity without direct carbon emissions. By substituting coal or natural gas plants with SMRs, utilities can significantly cut greenhouse gases. In many countries, nuclear power already forms a large portion of low-carbon energy, and SMRs could expand that share even more.
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Scalability and Grid Flexibility
One major selling point of SMRs is scalability. Instead of committing to a massive reactor from day one, utilities can build capacity module by module. This flexibility suits:
- Remote or Island Grids: Places relying on expensive diesel shipments can switch to SMRs for long-term reliability.
- Growing Economies: Rapidly expanding regions can add SMR modules to match rising demand.
- Distributed Power: Several smaller reactors scattered throughout a region can help balance the grid, reducing transmission bottlenecks.
SMRs work well in remote areas, but some can be used in cities too. They come with added safety features, like placing reactors underground.
For example, Holtec International plans to set up its first two SMR-300 reactors at the Palisades Nuclear Generating Station in Michigan. This shows that SMRs can be used in different settings.
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Enhanced Safety Profile and Efficiency
New nuclear technology uses passive safety systems, simpler designs, and smaller cores. These features lower the risk of severe accidents. This generation aims to ease public fears from past disasters like Chernobyl and Fukushima.
Notably, most SMRs require refueling every 3–7 years, compared to every 1–2 years for large reactors. Some designs promise up to 20 years of continuous operation without refueling. This extended refueling interval enhances SMR’s operational efficiency.
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Cost-Effective Deployment
Traditional nuclear plants often exceed $10 billion in construction costs and can take more than a decade to build. In contrast, SMRs range from $300 million to $2 billion per unit.
The levelized cost of electricity (LCOE) for SMRs is about $50–$100/MWh. This is a bit higher than large reactors. However, SMRs are competitive because they can scale well and have lower financial risks.
Moreover, traditional reactors take 8–15 years, whereas SMRs can be built in 3–5 years due to modular assembly. The modular construction approach allows for faster SMR deployment than traditional units.
SMRs have a lifespan of 40–60 years. Standardized reactor components let developers cut SMR construction costs by 30-50%. The modular nature of SMRs facilitates easier decommissioning processes.
Thus, SMRs aim to:
- Lower capital costs by standardizing reactor components.
- Speed up on-site assembly with fewer labor-intensive processes.
- Reduce financial risk for investors, as smaller reactors mean smaller upfront loans.
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Reliable Baseload Power and Potential for Lower Electricity Prices
While renewables like wind and solar are integral to a clean energy future, they are intermittent. SMRs can provide a stable baseload that complements renewables, ensuring the lights stay on when the sun doesn’t shine or the wind doesn’t blow.
Even better, SMRs have the potential to lower electricity prices in the long term as production scales up and costs decrease. Initially, electricity from SMR may be more expensive than from large reactors due to high startup costs.
But modular construction and faster build times can lower costs later. Also, government incentives, tax credits, and carbon pricing can make SMRs more affordable. This could make them a strong competitor to fossil fuels.
Regulatory & Permit Process for SMRs: A Step-by-Step Guide
Navigating the regulatory landscape is one of the most significant challenges for SMR deployment. Here’s how developers, investors, and policymakers can streamline compliance while addressing public and environmental concerns.
Why Regulatory Compliance Matters for SMRs
- Safety Assurance: Ensures SMR designs meet rigorous safety standards for radiation control, waste management, and emergency preparedness.
- Public Trust: Transparent processes help counter skepticism linked to historical nuclear accidents.
- Carbon Credit Eligibility: Compliance with low-carbon standards is often required to qualify for emissions trading programs.
Key Steps in the SMR Licensing Process
Based on frameworks from the IAEA, Canadian Nuclear Safety Commission (CNSC), and U.S. NRC:
| Stage | Key Actions | Timeline (FOAK)* |
| Pre-Licensing Review | Vendor Design Review (VDR), early stakeholder engagement, gap analysis | 1-2 years |
| Site Permitting | Environmental assessments, seismic studies, public hearings | 2-3 years |
| Design Certification | Safety case submission, passive system validation, waste management plans | 3-5 years |
| Construction License | Module fabrication approval, cybersecurity protocols, workforce training | 1-2 years |
| Operational License | Commissioning tests, emergency response drills, fuel loading approval | 1-3 years |
FOAK = First-of-a-Kind Reactor. Timelines shorten for nth-of-a-kind (NOAK) projects.
Global Regulatory Strategies
Canada:
- CNSC’s Graded Approach: Applies risk-informed regulations (e.g., reduced requirements for microreactors <10 MWe).
- Vendor Design Review (VDR): Optional pre-licensing service to resolve technical/regulatory issues early.
USA:
- 10 CFR Part 52: Streamlines combined construction/operation licenses (COLs) for SMRs with passive safety features.
- NRC Fee Reduction: Proposed legislation to cut licensing fees for advanced reactors by 50%1.
EU:
- Euratom Harmonization: Drafting unified standards for SMRs across member states to reduce duplication.
Top 3 Regulatory Challenges
- Public Perception
- Solution: Proactive community engagement (e.g., CNSC’s mandatory Indigenous consultations in Canada).
- Legacy Rules for Large Reactors
- Solution: Adaptive frameworks (e.g., IAEA’s SMR Regulators’ Forum for knowledge sharing).
- High Costs
- Solution: Government risk-sharing (e.g., Canada’s $970M Strategic Innovation Fund for SMR prototypes).
How to Accelerate SMR Approvals
- Leverage Digital Twins: Use AI-powered simulations to validate safety systems pre-construction.
- Adopt Modular Licenses: Bundle permits for multi-unit SMR farms (e.g., NuScale’s 12-module plant in Idaho).
- Partner with Regulators Early: 85% of delays stem from late-stage design changes.
RELATED: What Does the U.S. Need to Triple Its Nuclear Capacity by 2050? DOE Explains…
Challenges Facing SMRs
Some issues are faced by small modular reactor developers globally, including these five major ones:
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Regulatory Barriers
Government policy affects SMR adoption. Regulations, tax incentives, and subsidies play a crucial role in SMR adoption. The U.S., Canada, and the UK have made policies to speed up SMR development. Government support is pivotal in overcoming financial and regulatory hurdles.
Nuclear regulation is stringent for good reason. Legacy reactor rules slow SMR approvals, but Canada’s CNSC for example now fast-tracks permits using AI risk assessments. Many rules were written for large reactors, leaving regulators to adapt or create new frameworks for SMRs. This can lead to delays, increased costs, and uncertainty for investors.
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High Initial Costs
SMRs aim to be cheaper than traditional reactors, but they still cost hundreds of millions to build. This high price can scare away smaller utilities or countries. They might prefer cheaper options like natural gas or coal.
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Nuclear Waste and Public Concerns of Opposition
All nuclear reactors, including SMRs, produce radioactive waste. Communities still worry about storing nuclear waste long-term, despite SMRs’ smaller fuel cores. Building a deep geologic repository is a solution, but it requires political will and community consent—both of which can be hard to secure.
Common concerns or opposition include nuclear waste, safety risks, proliferation potential, and cost overruns. Public perception is improving as advanced designs enhance safety and efficiency. However, skepticism remains due to historical issues with nuclear energy projects.
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Competition from Renewables
Solar and wind prices have dropped a lot in the last ten years. This makes them very competitive. SMRs need to show they can be economically viable. They should be seen as reliable partners to renewables, not competitors.
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Financing and Market Adoption
Banks and investors view nuclear projects as risky, especially with new technologies. Governments can lower this risk with loans, tax breaks, or guaranteed contracts. These incentives vary by region. Until the first wave of SMRs is successfully deployed, financial uncertainty may hold back their adoption.
What are the Leading SMR Projects and Technologies Under Construction?
While there are over 80 SMR designs and concepts worldwide, not all have made significant progress or development yet. Here are some of the leading SMR projects or technologies and the companies behind them:
NuScale Power (USA)
- Key Features: NuScale’s SMR design features a 50 MWe module, with the option to scale up to 12 modules at a single site (for a total of 600 MWe).
- Regulatory Milestone: In 2020, NuScale was the first company to win U.S. Nuclear Regulatory Commission (NRC) design approval for an SMR.
- Deployment Outlook: The company targets commercial operation in the late 2020s, with pilot projects in the western United States.

Rolls-Royce SMR (UK)
- Size and Goals: Rolls-Royce plans a 300 MWe reactor, hoping to deploy in the UK and beyond by the early 2030s.
- Cost Strategy: Leveraging its history in aerospace and advanced manufacturing, Rolls-Royce aims to cut costs and shorten build times with factory-fabricated modules.
- Focus: Compete on both cost and reliability to replace older fossil-fired plants and help the UK achieve net-zero carbon targets.

TerraPower’s Natrium (USA, Backed by Bill Gates)
- Coolant Innovation: Uses liquid sodium as a coolant. Boasting better heat transfer and improved safety over traditional water-cooled designs.
- Energy Storage: Integrates a molten salt energy storage system. This allows the reactor to ramp up power output during peak demand.
- Timeline: Aims to showcase a demonstration plant in the early 2030s. Particularly in regions with high renewable penetration.

GE Hitachi BWRX-300 (Japan & USA)
- Simplified Boiling Water Reactor: GE Hitachi’s design reduces the number of components. It aims for a lower cost and faster regulatory approval.
- Project Momentum: Multiple North American utilities have shown interest. Some Canadian provinces look at the BWRX-300 to replace aging coal facilities.
- Collaboration: Works closely with the Canadian Nuclear Safety Commission (CNSC) for design review and licensing.

Oklo (USA)
- Microreactor Approach: Oklo’s concept focuses on very small reactors (around 1-2 MWe) designed for off-grid or remote sites.
- Fuel Cycle Innovation: Oklo aims to use HALEU and advanced fuel forms, potentially drawing from spent fuel from older reactors.
- Licensing Path: In 2020, Oklo received a site permit from the NRC for its Aurora reactor, although licensing processes are ongoing. The company seeks to show that microreactors can be delivered quickly and operate for years without refueling.

NANO Nuclear Energy (NNE, USA)
- Advanced SMR Research: NNE is working on microreactor and SMR designs that use innovative technology and materials for both safety and efficiency gains.
- Focus on Modularity: Like other SMR developers, NNE plans to rely on modular and potentially additive manufacturing methods to reduce costs.
- Market Position: Targets niche markets, including remote communities, island nations, and industrial sites in need of consistent power but lacking large-scale infrastructure.

Canada’s SMR Roadmap
Canada is positioning itself as a global leader in small modular reactor technology. The country has active SMR projects in Ontario, Saskatchewan, and New Brunswick. These projects aim to provide clean and reliable energy. They also support economic growth.
The Canadian Nuclear Safety Commission (CNSC) has established a structured regulatory process, including vendor design reviews, to streamline SMR licensing. This proactive approach ensures safety while accelerating deployment.
Canada has abundant uranium resources and a strong nuclear industry, making SMRs a key part of its energy and export strategy. The country plans to develop and export SMR technology. This will help other countries cut carbon emissions. It will also strengthen Canada’s position in the global nuclear market.
For more information on these and other SMR projects, visit trusted sources. Check out the World Nuclear Association (https://world-nuclear.org) and the IAEA’s SMR platform (https://www.iaea.org/topics/small-modular-reactors).
SMRs and Big Tech Companies: The Future of Data Centers and AI
The fast growth of artificial intelligence (AI) is driving up energy use in data centers. Right now, they make up about 2% to 3% of total U.S. power consumption. This number could reach 9% by 2030. This rise is putting pressure on current power systems. As a result, tech giants are looking for new energy sources to meet their increasing demands.
To tackle these challenges, big tech companies are looking at nuclear energy, especially small modular reactors. SMRs provide a reliable and scalable power source. They can be placed near data centers, ensuring a steady energy supply and reducing environmental impact.
Here are some of the latest moves by the big tech companies involving SMR deals and partnerships.
Google’s Initiative
In October 2025, Google made a deal with Kairos Power. They aim to develop several SMRs to power its AI data centers. The first reactor should be operational this decade, depending on regulatory approvals. More units are planned by 2035.
Amazon’s Strategy
Amazon Web Services (AWS) wants to add nuclear power to its energy mix. The company plans to hire a principal nuclear engineer to lead the development of modular nuclear plants. These plants aim to provide carbon-free energy to AWS data centers. This step shows Amazon’s commitment to sustainable energy for its growing AI operations.
Microsoft’s Collaboration
Microsoft partnered with Constellation Energy to look into using nuclear power for its data centers. As part of this, they plan to revive a unit of the Three Mile Island nuclear plant in Pennsylvania. It’s an effort to reuse existing nuclear facilities to meet today’s energy needs.
Meta’s Exploration
Meta, the parent company of Facebook, is exploring nuclear reactors to meet the electricity needs of its data centers and AI projects. The company seeks developers to create nuclear solutions that fit into their infrastructure. This reflects a growing trend in the industry for adopting nuclear energy.
Recent announcements and agreements related to the procurement of nuclear energy for the data center sector (as of 2024 – from the IEA report).

SMRs for Data Centers and AI: Future Outlook
As AI continues to evolve, data centers require much more energy. Using nuclear power, especially via SMRs, gives tech companies a way to meet these demands sustainably.
Interestingly, SMRs can be used for other non-electricity applications like hydrogen production.
SMRs can produce high-temperature steam. This steam is useful for hydrogen production, desalination, and industrial heating. So, SMRs are versatile energy solutions and this versatility enhances their value proposition.
However, many are wondering whether SMRs are vulnerable to cyberattacks or security threats.
SMRs use advanced digital security. However, relying on remote operations and automation raises cybersecurity risks. Potential threats include hacking attempts on control systems, data breaches, and software vulnerabilities.
Governments and regulatory bodies are creating strict cybersecurity rules. They are using AI for monitoring and encryption to stop cyber threats. Ensuring robust cybersecurity is essential for maintaining operational safety and preventing unauthorized access to SMRs.
SMRs and Carbon Credits
Many nations have set net-zero targets, which they plan to reach through a mix of renewable power, efficiency measures, and low-carbon technologies like SMRs. Each SMR module that displaces a coal or gas plant directly reduces annual CO₂ emissions. This, in turn, can earn the company with carbon credits.
Cap-and-trade systems allow companies that emit less than a set cap to sell or trade carbon credits to those exceeding it. Nuclear power—given its low-carbon credentials—often qualifies for such credits or similar offset programs. While policies vary, SMRs could generate carbon credits if the local system recognizes nuclear as a zero-carbon source.
Investors today want to align their portfolios with Environmental, Social, and Governance (ESG) principles. They often seek projects that can prove they cut emissions. SMRs can qualify if they show clear benefits for carbon reduction and have strong safety records. This makes them more attractive, especially for big institutions that need to green their portfolios.
The Future of SMRs
So, with all the interest and hype about small modular reactors, what does the future look like? Some of the major trends to watch out for include:
Global Expansion
The IAEA notes over 70 SMR designs in various stages of development worldwide. Countries with aging reactors (like Japan) may view SMRs as a natural upgrade path while emerging economies in Africa and Asia could leapfrog to SMRs instead of relying on large-scale fossil plants.
Integration with Renewables
As more wind and solar capacity come online, grid intermittency becomes an issue. SMRs can provide steady baseload power, balancing out renewables. Some designs (like TerraPower’s Natrium) even offer integrated energy storage, allowing flexible power output to match demand peaks.
Next-Gen Fuels and Concepts
Research continues on advanced reactor concepts, including molten salt, gas-cooled, and thorium-fueled designs. These could further reduce waste, operate at higher temperatures (boosting efficiency), and enhance safety. Oklo and NNE exemplify companies pushing the boundaries by exploring microreactors and new fuel cycles that might recycle spent fuel from older plants.
Advanced Manufacturing
3D printing and robotic assembly could slash the time and cost needed to build reactor modules. AI-driven software also optimizes reactor core design, fuel usage, and maintenance schedules. Over time, these advances may make SMRs more competitive with other forms of clean energy.
Remote & Specialized Applications
SMRs’ small footprint and long fuel life (sometimes operating for several years without refueling) make them especially attractive where logistics pose major challenges. This is where microreactors come in.
Microreactors are smaller than SMRs, differ from the latter, and generate less than 10 MW. They can power mines, military bases, and remote communities that lack reliable access to national grids.
Companies like Oklo and NANO Nuclear Energy are leading this sector. Microreactors offer even greater flexibility and can be rapidly deployed.
RELATED: Are SMRs The Future of Nuclear Energy? Oklo Leads the Charge
Regulatory/Policy Support
Recently, U.S. President Donald Trump’s 2025 executive order established the National Energy Dominance Council to expand energy production, streamline regulations, and strengthen U.S. energy leadership. The order prioritizes all energy sources, including nuclear, oil, gas, and renewables.
It aims to reduce foreign dependency, boost economic growth, and enhance national security. A key focus is cutting red tape and accelerating private sector investments in energy infrastructure.
Conclusion
Small Modular Reactors (SMRs) could bring clean and reliable nuclear power. They can meet the rising electricity demand and help fight climate change. SMRs offer benefits like modularity, safety improvements, and cost savings. These features may help solve problems that have slowed nuclear power’s growth in the past.
Nevertheless, hurdles remain. Nevertheless, hurdles remain. Regulatory systems must adapt, and public views need to change. Also, financing structures should be innovative to support new projects.
Leading companies—like NuScale, Rolls-Royce, TerraPower, GE Hitachi, Oklo, and NANO Nuclear Energy (NNE)—are setting the stage with pilot plants and fresh designs. Government support and better policies on carbon credits could speed up SMR deployment around the world.
As the planet races toward net-zero targets, small modular reactors hold the potential to fill critical gaps in our energy mix. SMRs aren’t the only answer. Renewables, storage tech, and efficiency also matter. Still, SMRs could be key to a stronger, sustainable global energy system.
Key Takeaways
- SMRs are nuclear reactors of up to 300 MWe capacity, offering modular construction and zero direct carbon emissions.
- Safety is improved through passive systems and smaller cores, helping mitigate public fears about nuclear power.
- Leading Developers include NuScale, Rolls-Royce, TerraPower, GE Hitachi, Oklo, and NNE, each with unique designs and target markets.
- Carbon Credits could enhance SMR finances if regulations recognize nuclear as a carbon-free source.
- Future Prospects are bright, but challenges like regulation, cost, and public acceptance must be addressed for SMRs to scale globally.
The post What is SMR? The Ultimate Guide to Small Modular Reactors appeared first on Carbon Credits.
Carbon Footprint
Why I’m Pro-Nuke Now: Beginning
I composed this essay over much of 2026, as I was writing Beyond Vogtle — my detailed study (co-authored with James Boucher) of U.S. nuclear costs from the 1980s post-Three Mile Island reactors to the Vogtle 3 and 4 units completed earlier in this decade. It traces my journey from nuclear power doubter to proponent.
My story is both general and personal: what was changing in the wide world of nuclear power, energy policy and climate; and how I viewed those changes. I hope this mode of story-telling resonates with a wide audience and also provide a backdrop to “Beyond Vogtle.”
It’s in three parts.
Detail from 1979 rally poster. Full poster appears below.
The first installment begins at the big Washington rally called to mark the Three Mile Island reactor accident, and covers the recession of nuclear dread, the advent of virtually always-on reactor operation, and nuclear’s status as the least carbon-emitting energy supply technology.
Installment #2 begins with the failure (to date) of carbon tax advocacy — “A Climate Cure No One Wanted” — and continues with the closure of Indian Point and the concurrent slow dissolve of my dream that renewable energy could do it all.
The third and final installment begins with a slight detour in which I contrast the appalling human damage from automobility with nuclear power’s increasingly remote dangers, and then return to energy policy with a fresh way to regard nuclear power’s potential contribution to decarbonizing U.S. grids.
Thank for reading. Enjoy. And be sure to look at Beyond Vogtle: What History Tells Us About the Cost of New Nuclear (yes, that’s the full title).
— C.K.
* * * * * * * * *
I’m pro-nuclear power. Big time.
I don’t just want the U.S. to keep running its 95 extant reactors. I want us to build more. Lots more. Hundreds.
I’m not alone. Public opinion is shifting toward nuclear power. But I came to that conclusion after spending years arguing the other side. From the mid-1970s to the late 1980s, I published a raft of critical analyses that got a good deal of public attention ― and even some traction within the nuclear industry itself. My core argument was that the cost of building nuclear plants was rising much faster than the costs of competing sources of energy. The main driver, I said, was a cascade of safety-requirement changes triggered by widespread fears of reactor accidents.
Here’s the full poster.
That work earned me a speaking spot at the massive May 6, 1979 rally in Washington demanding a halt to reactor construction in the wake of the March 28 meltdown at Three Mile Island in Pennsylvania. In the weeks before the rally, my research was cited in hundreds of news stories. At the Capitol, I stood alongside consumer advocate Ralph Nader, the leading figure in the U.S. antinuke movement; actress Jane Fonda, whose new film, “The China Syndrome,” had eerily foretold the Three Mile Island meltdown; and folk-rock icon Jackson Browne. I told the cheering throng that nuclear power was finished.
Cost overruns and canceled reactor projects were putting billions of dollars on the line, and I spent much of the next decade in courtrooms all over the country, explaining patiently to utility regulators why investors, not customers, should bear those losses. I eventually moved on to other public policy work, sparking big-city bicycling and helping bring congestion pricing to New York. But I kept watching nuclear power and the broader energy landscape. Over time, what I saw led me to turn from skeptic to supporter. Here’s why, in eight parts.
1. Fear and Dread Recede
Ask 100 random people today what “TMI” means, and at least 90 will say “Too Much Information.” Maybe one will mention the 1979 accident at Three Mile Island.
That’s a real shift.
The 1970s were commercial nuclear power’s first decade, and the Three Mile Island accident brought it to a terrifying close. Sixty hours into the slow-unfolding crisis, as fears grew that a “hydrogen bubble” in the reactor might explode and rupture the containment dome, CBS Evening News anchor Walter Cronkite captured the nation’s dread: “The world has never known a day quite like today. It faced the considerable uncertainties and dangers of the worst nuclear power plant accident of the atomic age. And the horror tonight is that it could get much worse.”[1]
The stricken reactor was eventually stabilized. But a combination of soaring costs and public apprehension brought an end to nuclear power’s rapid expansion in the United States.
Cronkite’s warning was about Three Mile Island itself, but it seemed to foreshadow more disasters to come. Yet since 1979, the U.S. nuclear industry has accumulated nearly 20 times as much reactor operating experience as it had built up in its entire history before the meltdown, without a sequel.[2] Like the dog that didn’t bark, this quiet fadeout of reactor calamities is an overlooked shift ― and it is prompting a rethink of long-held certitudes about nuclear power.
With each passing year there are fewer people who grew up with dread from Cold War-era A-bomb drills and weapons test fallout that got bundled into nuclear power. There are more young people like Zeke, a Brooklyn high-schooler who in 2019 went to Battery Park City to greet climate activist Greta Thunberg after her sail-powered trans-Atlantic voyage, but who this past May called fears about nuclear power “over-exaggerated.”[3] (Thunberg herself has said that Germany made a mistake by phasing out its nuclear plants, since it led to a sharp rise in coal-fired electricity.)
I’ve heard the same sentiment in hundreds of casual conversations over the past decade ― at climate rallies and on Trader Joe’s checkout lines, in California and in New York. These conversations suggest that the oppositional currents that once compelled federal nuclear regulators to keep piling on costly new safety requirements are losing force.
2. Permanent Peak Performance
Even before construction costs began to soar in the 1970s, nuclear power had another Achilles heel: spotty operating performance.
Throughout the 1970s and 1980s, the U.S. nuclear power sector struggled to maintain even a 60 percent “capacity factor” ― a measure of how much of a plant’s potential output it generates. That’s a dismal rate for equipment that’s expensive to build. I know this because I researched and wrote the first full-length study of shortfalls in U.S. nuclear plant performance, in 1976.[4]
That started to change in the mid-1980s. Plants finished safety upgrades required after Three Mile Island. The industry began sharing best practices ― and mistakes to avoid. Economic incentives helped too, as utility earnings became tied to how often plants actually ran.
A remarkable turnaround, though seldom credited in climate and nuclear discourse.
The turnaround has been dramatic. Since 2000, U.S. nuclear plants have averaged 90 percent capacity factor ― a huge leap from the earlier 60 percent. In effect, downtime has dropped four-fold, from 40 percent of the time to just 10 percent. Repair jobs and retrofits that used to drag on are now precision-scheduled like the train heist in “Breaking Bad.”
The higher reliability brings a huge symbolic benefit. In the 1970s, U.S. reactors seemed to stumble from one fiasco to the next. In Alabama, a technician using a lit candle to locate an air leak started a fire that burned through a thousand cables and knocked two brand-new reactors offline for 19 months. At some ocean-cooled plants, saltwater corroded delicate heat-transfer tubes, forcing protracted repairs. Profits and industry morale took a beating, and nuclear power became a punchline on “The Simpsons.”
Those days are long past. Nuclear power, uniquely, has blossomed into both grid bulwark and climate hero. Thanks to those higher ― much higher! ― capacity factors, each nuclear plant now displaces 50 percent more carbon-emitting power generation than it used to.[5] In fact, at a 90 percent capacity factor, a kilowatt of nuclear power delivers double or triple the climate benefit of a kilowatt of wind power (which averages 30 to 40 percent capacity factor) and roughly five times that of solar (15 to 20 percent) ― a crucial distinction that’s often missing from gushing coverage of renewable energy.
3. Climate to the Fore
Nuclear power’s newfound operational mastery would matter much less but for the urgency of the climate crisis and the persistence of U.S. and global carbon emissions. Like wind and solar, nuclear power generates electricity without burning carbon.
Squint to see that nuclear lifecycle greenhouse gas emissions range from 5.1 to 6.4 (in g CO2 equivalent per kWh); analogous range for solar-PV is 7.4 – 83.0; wind, 7.8 – 23.0. Source, Dinon et al., in report linked in this section’s second paragraph.
It is true that fossil fuels are implicated in nuclear power’s supply chain. Uranium mining uses petroleum, and enriching nuclear fuel requires electricity. But even counting upstream carbon, nuclear power’s climate footprint is smaller than that of wind, solar or hydropower, according to an authoritative 2022 analysis by a multinational team for the UN Economic Commission for Europe. (Their finding matched that of the similarly comprehensive 2018 report by the UN-chartered Intergovernmental Panel on Climate Change.[6])
That’s another big change. In nuclear power’s early years, uranium fuel enrichment was so energy-intensive that the three U.S. “gaseous diffusion” plants were said to consume 10 percent of all electricity used by American factories. But diffusion enrichment has given way to gas centrifuges and, more recently, laser isotopic separation ― methods that use 20 times less energy to isolate fissile U-235 from U-238.
The bottom line: kilowatt-hour for kilowatt-hour, nuclear-generated electricity is at least as effective as solar and wind at cutting climate pollution. Meanwhile, Hurricane Katrina, Superstorm Sandy, “heat domes” and wildfires, and, in August, the first Himalayan glacial collapse, have made once-hypothetical climate death and disruption a daily reality. More than rising electricity demand from A.I., it’s the climate crisis that’s driving renewed interest in nuclear power.
Click here for the second installment, Why I’m Pro-Nuke Now: Beginning.
[1] Quoted passage is from a local (PA) news site, though the an archived Channel 2 broadcast it cited is no longer on line.
[2] The sole “near-miss,” and a major one, was the 2002 discovery by operators at the Davis-Besse nuclear plant near Toledo, OH of extensive corrosion of the reactor vessel head — a vital barrier against loss of coolant and release of radiation. The U.S. General Accounting Office sternly rebuked the Nuclear Regulatory Commission for failing to identify and prevent the corrosion. See GAO, Nuclear Regulation: NRC Needs to More Aggressively and Comprehensively Resolve Issues Related to the Davis-Besse Nuclear Power Plant’s Shutdown, GAO-04-415, May 2004.
[3] In-person conversation at People’s Policy Conference at the New School for Social Research in New York, May 2, 2026.
[4] C. Komanoff, Power Plant Performance: Nuclear and Coal Capacity Factors and Economics (15 MB pdf), Council on Economic Priorities, 1976.
[5] Dividing today’s 90% uptime by the former 60% yields 1.50, indicating 50 percent more kilowatt-hours per kW.
[6] IPCC Annex III report, Technology-Specific Cost and Performance Parameters, 2018. See table on p. 1333.
Carbon Footprint
Why I’m Pro-Nuke Now: Centerpiece
This is the second part of a three-part post. It begins with the failure of carbon tax advocacy and continues with the closure of Indian Point and the concurrent dissolution of my dream that renewable energy could do it all. Part I, “Beginning,” started with the Three Mile Island accident and covered the decline of nuclear dread, the advent of splendidly reliable reactor operation, and nuclear’s climate-hero status. It’s available here. — C.K.
4. A Climate Cure No One Wanted
Nuclear fission, wind turbines, solar panels. Each is a kind of miracle, creating electricity from sunlight, air currents, or the splitting of atoms rather than by setting things on fire. But to economists focused on decarbonization, a greater miracle would have been the widespread adoption of carbon taxes, or, as some prefer to call it, a “price on carbon” — a fee added to fossil fuels’ market price based on their carbon content. Such a tax would shift incentives across the economy away from using fossil fuels, cutting production of the main greenhouse gas, carbon dioxide.
Economists trace the carbon tax idea to the early 20th century British economist Alfred Pigou and his conception of “externalities” ― social costs, like pollution, that aren’t reflected in market prices, and are dumped on communities “external to the process.” My interest dates to the early 1970s, when I was a fledgling environmental analyst in New York City government. I had a front-row seat as an ingenious “sulfur surcharge” eliminated the price advantage of dirty, high-sulfur fuel oil, foiling an eleventh-hour attempt by the oil industry to undercut a groundbreaking clean-air regulation.
Much later, in 2007, I co-founded the Carbon Tax Center, an organization built around the idea of taxing fossil fuels by their carbon content. We proposed a national carbon tax starting at $15 per ton of CO2 and rising in annual steps to $100 within a decade. Our modeling suggested that by then, the myriad changes driven by the financial rewards for burning less carbon would be cutting U.S. emissions by nearly a third ― far more than conventional energy-efficiency standards or clean-energy subsidies.
To be clear, this wasn’t an either-or choice. A carbon tax was unusual in that it reinforced nearly every other decarbonization measure rather than competing with it. But what really set carbon pricing apart was its reach. Carbon taxes would reward every action that reduced fuel use ― not just buying more fuel-efficient cars, but driving less overall; not just laws mandating energy-efficient buildings, but reforming zoning to let new homes be built in town instead of spreading into sprawl; and, in the power sector, switching from higher-carbon coal to lower-carbon gas and from gas to virtually zero-carbon solar, wind, and nuclear power.
A carbon tax would have worked something like New York’s congestion pricing program, which last year began charging drivers $9 a day to enter Manhattan south of 60th Street. Congestion pricing hits gridlock with a one-two punch. The first punch is the price itself: faced with the toll, enough car owners find driving no longer worth it, that traffic actually drops. The second punch is the steady stream of subway improvements funded from the toll revenue — station elevators, real-time train signals, new lines — which pull still more commuters out of cars. Just so, the “stick” of a price and the “carrot” of better alternatives reinforce each other.
I took part in the 20-year campaign that pushed congestion pricing across the finish line. Its advent — and survival — in Trump’s second term is heartening. But it also highlights, by contrast, how little headway has been made toward a U.S. carbon price.
That failure constitutes a tragically missed opportunity for nuclear power, given how much a $100-per-ton carbon price could strengthen its economics. Compared with burning natural gas, the dominant source of U.S. electricity today, a $100/ton CO2 price would give nuclear roughly the same competitive edge as shaving 40 percent off the cost to build new reactors. Or, put another way, that carbon price would be like doubling or tripling what gas-fired power plants pay for pipeline fuel — pushing prices back to pre-fracking scarcity levels.[7])
5. Losing Indian Point
In the spring of 2020, with the COVID-19 pandemic raging, my wife and I fled the city for our cabin in the Adirondacks. One morning I was outside the general store, loading groceries onto my bicycle, when my phone started buzzing. It was Dietmar Detering, someone I knew slightly as leader of the advocacy group Nuclear NY, calling from Queens. I picked up and said hello.
“You call yourself a climate activist,” Dietmar began, his voice sputtering with anger. “Indian Point is being taken apart, and you haven’t said a word to stop it. How dare you?”
I vaguely knew that a 2017 deal ― pushed by the self-proclaimed environmental group Riverkeeper and brokered by then-Gov. Andrew Cuomo ― was about to shut down the Indian Point nuclear plant, located on the Hudson River 35 miles north of midtown Manhattan. The older of its two reactors unit would (literally) get the chop within a week; its twin would follow in a year. Both reactor vessels would be cut to pieces and their radioactive components chemically dissolved. Once that process began, there’d be no turning back.
I stood there holding my phone, stunned. A near-stranger was berating me! I would have hung up, but there was something raw in his voice that I couldn’t ignore. I don’t remember exactly what I said ― probably some version of “don’t blame me.” After all, the carbon tax I’d spent years advocating would have made Indian Point too valuable to shut down. Then I offered what I thought was my strongest point: soon enough, Indian Point’s carbon-free electricity would be replaced by zero-carbon wind and solar anyway, so little harm would be done.
Then Dietmar lowered the boom.
“You don’t get it, do you?,” he said, his voice now cold. “Even if all those new solar panels and wind turbines get built, they won’t displace fossil fuels. They’ll just be replacing carbon-free nuclear electricity that was already protecting the climate. They can’t do both.”
“Wait. What? Say that again.”
“Think of it this way,” Dietmar said. “When new renewables have to replace an existing power source that was already displacing fossil fuels, like Indian Point, their net climate benefit is zero. The renewables you’ve been counting on to push out fossil fuels can’t do that job as long as they’re having to take the place of nuclear plants that were already doing the decarbonizing.”
Full disclosure: those aren’t Dietmar’s exact words. They’re actually mine, drawn from articles I later wrote for Gotham Gazette and The Nation, and from a letter I co-wrote with futurist Stewart Brand, yes, the “Whole Earth Catalog” guy, urging California Gov. Gavin Newsom to halt the planned closure of the Diablo Canyon reactors along his state’s coast. But they capture Dietmar’s central point: shutting down a working nuclear power plant ― or any large source of carbon-free electricity ― nullifies the climate benefit that new replacement wind and solar projects are supposed to provide.
Six years later, Indian Point’s closure still haunts me. Why didn’t I speak up? It’s how I imagine I’d feel if a climbing partner had died because of some mistake I made. In New York, where I live, I measure every increment of renewable energy against the carbon benefit we threw away when Indian Point was shut down and dismantled.
By that gauge, wind and solar look mediocre. Take those 42-inch square “balcony solar” arrays that Germans are buying like hotcakes ― they’re a neat idea, but it would take 50 million of them to match the carbon reduction Indian Point provided, as I wrote here in June. Or consider a rooftop solar setup for the City Island boathouse where my ecologically minded physicist pal stows his sailboat ― fine on its own, but matching Indian Point’s climate value would require solarizing 600,000 similar buildings across the state.[8]
Underneath these daunting numbers is Dietmar’s deeper point: all of this new renewable capacity should have been added on top of Indian Point, not built to replace it.
6. Renewables in a Dimmer Light
Solar and wind power were guiding passions of my adult life. From the 1970s onward, I savored every news story about the latest gains in solar efficiencies and blade lengths. Wind turbines especially stirred me, with their kinetic kinship to bicycles and futuristic look.
Befitting my mathematical bent, I would calculate how much fossil fuel each new wind farm would keep in the ground. For Cape Wind, intended as the first U.S. offshore wind farm, near Cape Cod, I consulted a digest of ballpark dimensions to illustrate how much coal the project would displace each year: enough to cover the entire playing field at Boston’s Fenway Park — foul territory included — in a pile three times the height of the park’s famed “Green Monster” outfield wall.[9]
While I was playing with those numbers, a Stanford mechanical engineering professor named Mark Z. Jacobson was launching a stream of papers spelling out just how many wind turbines and solar panels ― on land, at sea, on rooftops, on farmland or rangeland ― would be required to satisfy the energy needs of different states and countries.
A table in Jacobson’s paper for New York helpfully broke down how much energy had to come from each source. Offshore wind was his largest category, charged with supplying 40 percent of New York State’s energy year-round. The number of turbines: 12,700.
That figure should have given me pause. Filling that quota meant building a hundred Cape Wind projects in the waters off Long Island, even as well-heeled locals including Riverkeeper figurehead Robert F. Kennedy Jr. (yes, that Kennedy) and Walter Cronkite (yes, that Cronkite) were NIMBYing the actual Cape Wind project to death. Ditto, wind projects proposed for the next county over from our cabin in the Adirondacks.
None of those projects were ever built — not just because of local opposition, but also because of a lack of full-throated support from environmentalists who should have championed them for their climate value. Especially in liberal Northeastern states, it seemed impossible to build anything that asked property owners to tolerate construction disruption or changed views, decarbonization be damned.
You might expect the outlook for Jacobson’s all-renewables vision for New York to be improving. Wind turbines are now so prodigious that he can propose 8,000 15-gigawatt turbines instead of 12,700 5-gigawatt ones.[10] And solar power has captured the public’s imagination in a way wind power has not — it’s no accident that climate activist (and Jacobson acolyte) Bill McKibben titled his 2025 call-to-action book, “Here Comes The Sun.”
Nevertheless, the carbon-free electricity lost when Indian Point closed has gone almost entirely unreplaced. Nearly nine-tenths of the power it generated is being made up by burning natural gas — not due to corporate chicanery but because no other source has stepped up. (See chart below.)
And dreams of an all-renewables grid still have to contend with an intrinsic fault ― one even more disabling than the NIMBY opposition sparked by the projects’ thirst for land. That weakness is intermittency: the fact that wind and solar output varies not just day to day, but moment to moment, at the mercy of the weather.
Jacobson has doggedly calculated how many megawatt-hours of wind and solar would be needed to match New York’s ― and other states’ ― total annual energy use. But neither his nor anyone else’s atmospheric models are detailed enough, meteorologically, to verify that a 100% wind-water-solar grid could keep the power on continuously ― hour by hour, year in and year out. Building in extra capacity doesn’t solve this problem. Compensating for weather’s unpredictability by deliberately oversupplying wind and solar, or backing them up with batteries, may look good on paper. But either approach would be punishingly expensive and probably insufficient as well, without ample supplies of reliable, dispatchable power such as nuclear. If there’s no wind, having twice as many turbines won’t help.[11]
In New York, the political fallout from losing Indian Point’s copious ’round-the-clock carbon-free electricity is landing on Cuomo’s successor. With the plant’s closure having pushed New York’s carbon-reduction targets out of reach, Gov. Kathy Hochul this year bowed to reality and froze a 2019 law tying New York’s climate and energy future to renewables. Forces ranging from standard-issue Democrats to grassroots greens are pillorying Hochul as a sellout to Big Oil, though her proposal to add five large reactors across the state — she dubs it her Nuclear Reliability Backbone — is almost certainly a more assured path to decarbonization than the fashionable all-renewables approach.
Click here for the final installment, Why I’m Pro-Nuke Now: Conclusion.
[7] The two representations in the text of carbon pricing’s boost to new reactors’ economics are derived and sourced in my Sept. 2026 paper with James Boucher, Beyond Vogtle: What History Tells Us About the Cost of New Nuclear.
[8] Comparisons in this paragraph employ: 2,028 MW capacity and 90% capacity factor for Indian Point; 220 W capacity and 15% CF for balcony solar. 17 kW capacity and 20% CF for boathouse solar. 10 MW and 40% CF for each wind turbine.
[9] Cape Wind assumptions: 130 3.6-GW turbines and 40% capacity factor yield 1,641 GWh/year. Coal assumptions: 9,800 Btu/kWh, 11,500 Btu/lb of coal, 1.32 coal specific gravity, 62.4 lb of water per cubic foot. Calculations yield 132-foot-high coal pile covering Fenway Park’s 128,000 sq ft surface (est’d from http://www.baseball-statistics.com/Ballparks/Bos/index.htm). That is 3-4x Green Monster height of 37 feet, 2 inches, per Wikipedia.
[10] While Jacobson’s new offshore wind configuration would outproduce its predecessor by nearly two to one, he has also upped his forecast for total required energy, leaving constant offshore wind’s share 40 percent share.
[11] To take a recent example: at the onset of a late June – early July 2026 heat wave, New York State’s wind farms collectively were producing less than one percent of their rated 3,000-megawatt capacity. See my “Beyond Vogtle” report (FN 46) referenced in Footnote 7.
Carbon Footprint
Why I’m Pro-Nuke Now: Conclusion
This concludes my three-part post. Part I, “Beginning,” began with the Three Mile Island accident and covered the decline of nuclear dread, the advent of fabulously reliable reactor operation, and nuclear power’s climate-hero status; it’s available here. Part II, “Centerpiece,” covered the failure of carbon tax advocacy, the closure of Indian Point, and the dissolution of my dream that renewable energy could do it all; it’s available here. This part takes antinuclear activism to task for turning a blind eye to the far more lethal harms from unrestrained automobility, and then turns to the need to redefine “least-cost” decision rules guiding electricity investment. — C.K.
7. A More-Brutal Bête Noire
On a different, but as I’ll show, related topic: I had known for some time that deaths from being struck by a motorist were shockingly common in the U.S., with 300 a year in New York City alone. I had made that fact a central element in defending bicycling against the moral panic over ― of all things ― New York’s industrious bicycle couriers during the pre-digital 1980s. And as a bicycle commuter I had long jousted with drivers. But the death of oncologist Dr. Jie Zhang in 1994 forced me to consider driver-caused traffic violence as an assault on both public health and the moral order.
The horrific death in 1994 of physician and expectant mother Jie Zhang called into question antinuclear dogma that prioritized hypothetical reactor accidents over lethal dangers like unrestrained automobility.
A speeding driver hit and killed Dr. Jie outside Memorial Sloan Kettering Cancer Center on Manhattan’s East Side. She was nine months pregnant. As she lay dying, her colleagues at the hospital delivered her son, who survived. The newspaper ran a photo of the newborn in his father’s arms. My wife and our week-old son were safe at home. My good fortune was hard to bear.
What were the hazards of nuclear power, next to those of motorized traffic? There was and is no agreed-upon damage ratio between the two technologies. But in my eyes, the anti-nukers’ derogatory depictions of U.S. nuclear regulators seemed better suited to officials in charge of “auto safety.” In 2009, for example, after a spate of deaths in SUV rollovers, the National Highway Traffic Safety Administration required that roofs on new vehicles be able to support three times their already swollen weight. That rule led to wider windshield-obstructing structural posts , badly expanding SUV drivers’ blind spots. The result, according to a recent New York Times report, was a tidal wave of crashes that killed hundreds of pedestrians and cyclists and injured thousands more.
As a young attorney in the 1960s, Ralph Nader rocketed to fame by documenting how regulatory capture made cars excessively dangerous. His subsequent pivot to opposing nuclear power initially made sense but, over time, inadvertently left American pedestrians, cyclists, and occupants of smaller vehicles vulnerable not just to “vehicle bloat” but driver distractions and the “windshield perspective” of police, prosecutors and juries.
All the while, anti-nuclear activists keep pounding their drum, willfully ignoring U.S. reactors’ splendid post-seventies safety record (see Sections 1 & 2). With few domestic miscues to flog, they leaned instead into the faraway disasters at Chernobyl (1986) and Fukushima (2011). Those disasters were real enough, but they differed from the U.S. situation not just in location but also in root cause. Soviet and Japanese officials had downplayed reactor risks, while the U.S. nuclear enterprise had built a culture dedicated to containing them.
Even reactor radioactivity, like reactor accidents, is becoming another non-barking dog. We are half-a-century into the age of large-scale deployment of nuclear power, and not a single large-scale study has emerged that credibly pins increased morbidity and/or mortality on nuclear power plant operation. Moreover, the old Rubik’s Cube problem of nuclear waste disposal is yielding to engineered solutions. The hangup was never technical. It was political.
8. By All Means, Decarbonize
For half-a-century, nuclear power and renewable energy have circled each other like wary prizefighters.
The two weren’t simply antithetical, they were incompatible — logistically as well as culturally. One couldn’t be for both; you had to pick a side. That was the gospel of physicist Amory Lovins, whose revolutionary 1976 article in Foreign Affairs magazine, “Energy Strategy: The Road Not Taken,” upended energy policy debates and galvanized the antinuclear power movement.[12]
In Lovins’ influential framing, nukes epitomized “hard” energy — lumbering and brittle. Renewables — wind and solar — were “soft” — home-grown and “right-sized.” (This was before the relentless push for engineering efficiencies turned wind turbines into colossi and blanketed entire fields with solar panels.)
Fifty years on, the climate crisis has entered the ring and demanded that the rivals partner up. The choice now is carbon-burning vs. carbon-free. Further, the perilous timeline of the crisis has toppled another dictum, also traceable to Lovins: that the transition from fossil fuels must proceed under a “least-cost-first” hierarchy that turns to costlier energy sources only after first exhausting all of the less-expensive ones.
Once, that logic was persuasive. In a leisurely, decades-long transition, why not have the lowest-cost energy lead the way? Wherever a home solar array or a Great Plains wind farm could turn a profit, the thousand busy ants of capitalism could be trusted to deploy them. The climate-warping curve would bend, steadily, painlessly, bringing a more flexible and benign energy system into the bargain.
That was the idea. The reality is falling far short, as revealed by the stubborn persistence of U.S. carbon emissions.[13] The manifold causes have been touched on here; they include everything from traditional NIMBYism to viral versions built on conspiracy-mongering, along with supersized pickups, “sport utes” and the absence of robust carbon emissions pricing. The shale revolution and two Trump presidencies did their part as well, keeping fossil fuels cheap (until No. 47 made war on Iran), which added to the stock of carbon in the atmosphere and America’s stock of carbon-consuming cities and towns, farms and roadways.
In World Cup parlance, we’ve entered stoppage time. A new rule applies: nuclear power ― or any other fossil-fuel antidote ― need not pencil out as cheaper than solar or wind to merit a part in decarbonizing U.S. grids. Instead, we should pursue any energy source or energy-saving measure that displaces fossil fuel use at lesser cost than the harm caused by burning those fuels in the first place.
Feb. 11, 1985 cover.
Think of it like the hikers’ joke about the bear: I don’t need to outrun the bear, I just need to outrun you. In the same way, new nuclear plants don’t need to be cheaper per kilowatt-hour than solar or wind. Their electricity just needs to cost less than the added climate damage that would result from burning the fossil fuels that would otherwise fill the gap. And on that test, new nuclear power plants appear likely to succeed.
Let’s break that down.
What will new U.S. reactors cost to build?
This year I applied my statistical skills and power plant knowledge to the 49 most recently built U.S. reactors. Forty-seven of them limped to completion in the dozen years following Three Mile Island. At the time, their swollen costs so ravaged U.S. electric utilities that Forbes magazine termed the U.S. nuclear power program “the largest managerial disaster in business history.”
Nevertheless, my analysis of that cost data points to a path forward. I found that even if future reactor costs track past costs, a program that builds two or more reactors at each site and uses standardized designs will allow new plants to be built for an average cost of $8,200 per kilowatt of capacity, in 2025 dollars. At that price, building and running new reactors is almost certainly a lower-cost proposition than facing the ecological and human damage from burning equivalent fossil fuels.[14]
If anything, my figure is on the pessimistic side, since it bakes in the kind of shifting regulatory requirements that drove up costs so much in the post-TMI period. Even so, it comes to just half of what it cost to build the final two reactors — Georgia Power new Vogtle 3 and 4 units ― a project that nuclear power critics dredge up at every opportunity as proof that any new U.S. nuclear plant is doomed to be uneconomical.
An alternative visualization of this chart appears as Fig. 9 in “Beyond Vogtle.”
Just as important, the odds of future extreme overruns appear low. Using a probabilistic model, I found that the likelihood that a new twin-unit plant, built to a standardized design, will end up costing as much as Vogtle is slim ― the same odds, around 1.7%, as correctly calling six coin flips in a row.[15]
Will the long time to build new reactors undo their climate benefit?
Past nuclear plants seemed to take forever to finish. The 47 reactors whose costs I analyzed averaged nearly 12 years from initiation to completion ― a 50 percent worsening from their 1970s counterparts. Much of that added time traces back to Three Mile Island, which triggered design changes, equipment upgrades, and staffing shifts across the entire U.S. nuclear sector, each adding delays. Slowing demand for power also led some utilities to stretch out construction schedules on their own.
To nuclear power’s critics, these setbacks come with the territory. But reactors aren’t the only major infrastructure projects facing long timelines. Delays in building wind farms, transmission lines, and other accoutrements of renewable energy have prompted plenty of national hand-wringing too. Even balcony solar ― the latest face of decarbonization ― will need time to scale up. Electrical codes and fire regulations must be rewritten, and then the real challenge begins: installing roughly 25 million of these devices (at 220W each) to match the climate benefit of a single 1,000-megawatt reactor.
There’s also a déjà vu tinge to the complaint that nuclear power is too slow to help with the climate crisis. That argument easily predates Vogtle 3 and 4 ― the massive Georgia project that tested residents’ patience and wallets, but is now helping decarbonize Atlanta and hundreds of other cities. The goal isn’t to repeat Vogtle’s egregiously high cost, which doesn’t yet clear the bar set by the social cost of carbon. It’s to treat the climate fight as an ongoing effort to reduce harm by whatever effective means are available.
Balcony solar and giant nukes aren’t rivals ― they’re partners. Building Vogtle didn’t stop Georgians from putting solar panels on their roofs in 2015, and if balcony solar really is the money-saving no-brainer its supporters claim, there’s no reason it shouldn’t help rate-burdened Georgia families in 2027, too. “All hands on deck” is a cliché, but it fits here. The world has no time to wait ― it needs to decarbonize by every means available. Including nuclear power.
[12] Lovins’ Foreign Affairs article is available here. I recounted its momentous impact on energy policy and public discourse for The Electricity Journal in 10 Blows That Stopped Nuclear Power (Jan/Feb 1991).
[13] U.S. CO2 emissions circa averaged only 1 to 2 percent annual reductions over the period 2010-2025, a rate many times slower than needed to meaningfully address the climate crisis.
[14] See Komanoff & Boucher, “Beyond Vogtle,” op. cit., pp. 41-44.
[15] The chance of correctly calling six coin-tosses in a row is one-half raised to the sixth power, which is 1 in 64, or 1.56%, which more or less matches the 1.7% chance that a new nuclear plant will cost as much as or more than Vogtle 3 and 4. See Komanoff & Boucher, op. cit., Fig. 9.
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