Energy security has returned to the top of the EU agenda after the Iran war highlighted how exposed many member states remain to sudden oil and gas shocks, despite lessons from Russia’s invasion of Ukraine. Governments are rethinking efforts to diversify supplies and reduce external dependence, and nuclear power — especially small modular reactors (SMRs) — has re‑emerged as a policy option.

European Commission President Ursula von der Leyen called the bloc’s earlier move away from nuclear a “strategic mistake,” and Brussels is exploring extra funding to prioritize SMR deployment by the early 2030s. The prospect has reopened debates even in countries that phased out reactors: Germany’s Chancellor Friedrich Merz has called the phase‑out “irreversible” but a mistake, while Bavaria’s Markus Söder is pushing to build SMRs in his state. Industry voices argue nuclear remains unique in offering clean, scalable, and secure electricity.

What are SMRs?
SMRs are next‑generation reactors typically producing under about 300 MW — roughly a third of a conventional reactor’s output. Supporters say their modular, factory-built approach could lower upfront costs, shorten construction times, and boost safety through smaller fuel inventories and passive systems. Proponents also highlight SMRs’ ability to supply reliable electricity and high‑temperature heat for heavy industry.

Critics dispute those claims. Researchers such as M. V. Ramana argue SMRs often cost more per megawatt because many components and labor needs do not scale down linearly. Environmental groups warn that investing in unproven SMRs risks diverting funds from faster, cheaper measures like renewables, storage, and demand‑side management.

Nuclear’s role alongside renewables
EU countries have significantly expanded wind and solar. Renewables now provide a large share of electricity and around a quarter of total energy demand. But their variability prompts debate over the need for “clean firm” power that’s available on demand.

Advocates say nuclear — and SMRs in particular — can supply dependable low‑carbon baseload power and process heat for sectors such as chemicals, steel and cement that are hard to electrify. Critics counter that modern energy systems prioritize flexibility: plants that can ramp output, complemented by batteries, grid upgrades, and demand response, rather than baseload reactors that run continuously to remain economical. They argue a renewables‑centric system with sufficient storage and flexibility can meet decarbonization goals without new nuclear.

Safety and technical questions
Safety remains central to the SMR debate. Some designs promise enhanced safety features, smaller inventories of radioactive material, and passive shutdown systems that work without external power. But SMR concepts vary widely and lack a single standard design; only a handful of projects worldwide have been built to date, notably in China and Russia, each using different approaches.

Experts caution that new materials and novel configurations introduce distinct challenges that require further research. Coupling SMRs with hydrogen production, industrial heat, or desalination could add chemical and operational risks. And long‑term radioactive waste management remains an unresolved policy issue for all nuclear technologies.

Economics and industrial strategy
SMR economics in Western markets remain unproven. Proponents stress that a coordinated EU program emphasizing standardized designs, joint procurement and regulatory alignment could reduce costs and create an exportable industrial platform — an outcome compared to how Airbus unified Europe’s aviation sector. Without such coordination, supporters warn, the EU risks losing ground to rival suppliers from other geopolitical blocs.

Opponents note that historically nuclear projects have suffered from cost overruns and delays, and that many LMIC and private buyers may prefer cheaper, quicker renewable plus storage solutions.

Where the debate stands
SMRs have rekindled a complex policy argument: they offer the promise of reliable, low‑carbon firm power and industrial heat but face unanswered questions on cost competitiveness, deployment timelines, safety across diverse designs, and waste management. Some experts see a role for SMRs as part of a broader “clean firm” toolkit; others see nuclear investment as a diversion from scalable, flexible, lower‑risk pathways.

As Europe confronts renewed energy‑security pressures, the choice between scaling renewables and storage, investing in SMRs, or pursuing a mix will hinge on politics, financing, industrial strategy, and how quickly technology and regulatory frameworks mature. The debate over nuclear’s place in Europe’s energy future is far from settled.

Energy security has shot back up the European agenda as the Iran war highlights how exposed many member states remain to sudden oil and gas shocks — despite lessons from Russia’s invasion of Ukraine. The crisis has renewed efforts to diversify supplies and cut reliance on imports, and it has prompted a fresh push for nuclear power.

European Commission President Ursula von der Leyen called Europe’s earlier turn away from nuclear a “strategic mistake.” Brussels is weighing additional funding for nuclear and prioritizing deployment of Small Modular Reactors (SMRs) across the bloc by the early 2030s. Even in nuclear‑free Germany, debate is heating up: Chancellor Friedrich Merz called the phase‑out a “serious strategic mistake” but “irreversible,” while Bavaria’s Markus Söder argues it’s “time for a new era of nuclear energy” and plans SMR projects in his state. Henry Preston of the World Nuclear Association says nuclear remains “unique” in providing clean, secure and scalable electricity.

SMRs are next‑generation plants generally under 300 MW — roughly a third of a conventional reactor’s output. Supporters argue they will be cheaper, faster and safer to build. Critics call the EU’s renewed nuclear focus a “misplaced strategy.” M. V. Ramana of the University of British Columbia says SMRs can cost more per unit because materials and labor don’t scale linearly. Luke Haywood of the European Environmental Bureau warns that funding unproven SMRs is a “costly distraction”: too slow, too expensive, and years from deployment at scale.

The broader energy context matters. EU countries have massively expanded wind and solar: renewables now supply nearly half the bloc’s electricity and about a quarter of total energy demand. Proponents of nuclear argue it provides steady “baseload” power unavailable from intermittent wind and solar. Malwina Qvist of the Clean Air Task Force stresses that renewables plus flexibility alone may not deliver a zero‑carbon system; without clean firm power, countries fall back on fossil fuels. She contrasts Germany — which gets around 59% of its electricity from renewables but has a much higher grid carbon intensity — with France, where nuclear supplies roughly 67% of electricity at near‑zero carbon. Qvist sees SMRs as part of a “clean firm power” toolkit, noting modular design, lower upfront costs, and potential to supply industrial heat for hard‑to‑decarbonize sectors like chemicals, steel and cement.

Opponents argue nuclear is a poor fit for a renewables‑dominated system that needs flexibility. Modern grids favor rampable resources, storage and demand‑side measures over baseload plants that must run continuously to be economical. Ramana recommends demand‑side management, batteries and flexible generation rather than investing in SMRs, warning that nuclear funding could divert resources from these alternatives.

Safety and waste remain central concerns. Some claim SMRs are safer due to smaller cores, less fuel inventory and passive safety systems. But Sara Beck of Germany’s GRS cautions that safety can’t be generalized across dozens of divergent SMR designs; only two SMR projects — in Russia and China — have been built so far. Novel materials and new applications introduce specific safety challenges, and coupling reactors to hydrogen production, heat supply or desalination could create additional hazards such as chemical effects, cross‑contamination or explosion risks. Ramana also notes that all nuclear plants risk accidents with widespread contamination and that long‑term radioactive waste management remains unresolved despite decades of research.

Qvist accepts that SMR economics are not yet proven in Western markets but argues global demand for reliable low‑carbon power is growing. She advocates a well‑executed EU SMR program centered on standardization and coordinated procurement to create a competitive export platform — likening the potential to Airbus in aviation — and warns that failing to build such capabilities could cede technological and market ground to geopolitical rivals.

As Europe navigates energy‑security pressures amid shifting geopolitics and rising industrial demand for clean power, the debate over SMRs and nuclear’s role in the energy mix is likely to continue. Edited by: Kristie Pladson