## Does Existing Nuclear Power Have the Lowest Electricity Cost of Any Technology?

Yes — by a significant margin. The OECD Nuclear Energy Agency and the Electric Power Research Institute's newly published *The Costs of Generating Electricity 2025* finds that long-term operation of existing nuclear power plants delivers the lowest mean and median [levelized cost of energy](https://smrintel.com/glossary/lcoe) of any of the 23 technologies examined, with a range of **$39/MWh to $64/MWh**. That undercuts every competing generation source in the study, from gas to onshore wind to utility-scale solar.

The report, which covers 21 OECD member countries, confirms what nuclear operators have argued for years: once initial capital is amortized, existing plants produce power at a cost that new-build alternatives — low-carbon or otherwise — struggle to match. In most of those 21 countries, electricity currently costs **$100/MWh or more**, making the $39–$64/MWh range for existing nuclear a substantial structural advantage.

For the industry's core forward-looking question — can new nuclear compete? — the answer is conditional. NOAK (nth-of-a-kind) large light water reactors land at **$56/MWh to $87/MWh**, clearing the $100/MWh threshold. [First-of-a-kind (FOAK)](https://smrintel.com/glossary/foak) projects, however, cost roughly **double** the NOAK figure for large LWRs, and roughly **50% more** for SMRs.

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## What the NEA/EPRI Study Actually Measured

The joint NEA-EPRI report analyzed 23 electricity generation technologies across 21 OECD nations. Despite growing calls for more comprehensive cost metrics — including system costs, grid integration expenses, and capacity payments — the authors explicitly defend LCOE as still providing "useful insights," though they acknowledge its limitations.

The full picture of sub-$100/MWh low-carbon generation, per the report:

- **Existing nuclear (long-term operation):** $39/MWh–$64/MWh
- **NOAK large-scale nuclear:** $56/MWh–$87/MWh
- **Hydroelectric:** sub-$100/MWh in favorable geographies
- **Onshore wind and solar PV:** sub-$100/MWh only when system costs — grid balancing, backup capacity, transmission — are excluded

That last caveat is analytically significant and deserves scrutiny. Stripping system costs from wind and solar LCOE comparisons while including all fixed and variable costs for nuclear is a methodological asymmetry the report's authors acknowledge but do not fully resolve. For grid planners and utility executives building integrated resource plans, that excluded system cost figure is often where the real decision lives.

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## The FOAK-to-NOAK Gap Is the Central Problem for Advanced Nuclear

The most operationally important finding for the SMR sector is the size of the FOAK penalty. Near-term nuclear deployments — whether large LWRs or SMRs — carry substantially elevated costs driven by supply chain immaturity, workforce shortages, and the absence of serial construction experience. The report quantifies this gap starkly:

- Near-term large LWR costs are **roughly double** NOAK costs
- Near-term SMR costs are **roughly 50% higher** than their NOAK equivalent

The report states directly: "Should the NOAK promise be realized, however, nuclear energy will be able to provide 'round-the-clock carbon-free electricity at less than USD 100 per MWh."

That conditional framing matters. The NOAK cost curve only materializes through repeated builds, regulatory predictability, and sustained supply chain investment — none of which are guaranteed. For investors and DOE program managers, the FOAK-to-NOAK trajectory is the exact risk profile that advanced reactor commercialization programs must de-risk.

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## Capacity Factor Is More Consequential for Nuclear Than Any Other Technology

The report's analysis of [capacity factor](https://smrintel.com/glossary/capacity-factor) effects on LCOE yields a finding that cuts both ways for nuclear. Higher capacity factors reduce LCOE more sharply for nuclear than for gas or coal, because nuclear's cost structure is dominated by fixed capital costs rather than variable fuel costs. Run a plant at 90%+ capacity factor and the economics are compelling. Drop it to 60% capacity factor through cycling or market curtailment and the LCOE deteriorates faster than for any other technology in the study.

The report states: "Driven by their high share of fixed compared to variable costs, nuclear power plants are the most affected technology when operated at lower capacity factors. In an environment in which they can be operated at maximum capacity, they benefit instead from their low variable costs."

This is why [baseload power](https://smrintel.com/glossary/baseload) contracting — including the power purchase agreements now being signed with data center operators seeking firm, around-the-clock clean power — matters structurally for nuclear economics. A nuclear plant dispatched as a peaker or mid-merit unit would face a materially different LCOE profile than one running flat-out under a long-term offtake agreement.

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## Policy Implications: No Single Technology Wins Everywhere

OECD NEA Director General William Magwood's statement in the report provides the diplomatic framing: "There is no single technology that can meet every country's energy needs in every circumstance. Countries will need to make policy and investment choices that reflect their own priorities, resources, and electricity systems."

That is accurate but also somewhat deflective. The data is less ambiguous than the diplomatic language suggests: for countries with existing nuclear fleets, continued long-term operation is the lowest-cost decarbonization option in this dataset, full stop. For countries building new capacity, NOAK nuclear is cost-competitive with other clean firm options — but only once the FOAK learning curve is absorbed, which requires policy continuity and sustained build programs that most markets have not yet demonstrated.

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## Key Takeaways

- Existing nuclear long-term operation delivers **$39–$64/MWh LCOE** — the lowest mean and median of all 23 technologies in the NEA/EPRI study
- NOAK large LWRs reach **$56–$87/MWh**, clearing the $100/MWh threshold that defines competitive low-carbon generation across most OECD markets
- FOAK large LWR costs are **roughly double** NOAK; FOAK SMR costs are **roughly 50% higher** than their NOAK equivalent
- Onshore wind and solar PV only clear $100/MWh when system integration costs are excluded — a significant caveat for grid planners
- Capacity factor has a larger LCOE impact on nuclear than on any other technology in the study, reinforcing the economic logic of baseload contracting and data center PPAs
- The study covered 23 technologies across 21 OECD countries

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## Frequently Asked Questions

**What is the LCOE of existing nuclear power plants according to the NEA/EPRI 2025 report?**
The report finds existing nuclear plants operating under long-term operation agreements have an LCOE of $39/MWh to $64/MWh — the lowest mean and median of all 23 technologies analyzed.

**How do SMR costs compare to large LWR costs in the NEA/EPRI study?**
The report states near-term SMR costs are roughly 50% higher than their NOAK equivalent, while near-term large LWRs cost roughly double their NOAK figure. Both SMRs and large LWRs remain more expensive in near-term deployment than at NOAK maturity.

**Can nuclear power generate electricity below $100/MWh?**
Yes, under specific conditions. Existing plants already achieve this at $39–$64/MWh. NOAK large LWRs are projected at $56–$87/MWh. The report states that if the NOAK promise is realized, nuclear can deliver round-the-clock carbon-free electricity below $100/MWh.

**Why does capacity factor matter more for nuclear than other technologies?**
Nuclear has a high ratio of fixed capital costs to variable fuel costs. At high capacity factors, low variable costs dominate and LCOE is attractive. At lower capacity factors, the fixed cost burden is spread over less output, degrading economics more sharply than for gas or coal.

**Does the NEA/EPRI report include wind and solar system costs in its LCOE comparison?**
The report specifies that onshore wind and solar PV only fall below $100/MWh "as long as their system costs are excluded." System costs — grid balancing, backup capacity, transmission — are not included in those technologies' headline LCOE figures, which is a relevant limitation for direct technology comparisons.