The Feasibility of Restarting Belgium’s Nuclear Reactors: A question of political will
- 13 hours ago
- 16 min read
Updated: 9 hours ago
Belgium has closed five of its seven nuclear reactors, but opportunities for restarting remain. New energy demand and gas supply chain disruptions make nuclear energy essential for energy security and clean baseload power. No significant technical barriers prevent Belgium's nuclear restart, but swift action is needed.
Executive Summary
Belgium has shut down five of its seven nuclear reactors since 2022. Only Doel 4 and Tihange 3 remain in operation, with life extensions granted to 2035. Prior to its nuclear closures, Belgium was a net exporter of electricity, with an export surplus of about 8% of its total electricity consumption. By 2023, it had become a net importer due to the shutdown of two reactors. The subsequent closure of three more reactors has significantly increased Belgium’s reliance on electricity imports and exposure to volatile fossil fuel prices.
A Belgian nuclear restart depends solely on political will, which seems to be present. The move is popular, economical, and feasible. No insurmountable technical barriers have been identified. The successful life extensions of Doel 4 and Tihange 3 demonstrate that political and legal obstacles can be addressed. Reactor restarts in the U.S., illustrated by significant progress at the Palisades nuclear plant in Michigan, further prove the viability of reviving previously-shuttered plants. The new government has set a target of 8 gigawatts (GW) of nuclear capacity by 2035, with a portion expected to come from restarting existing reactors. However, decommissioning activities at the shuttered reactors have continued, and some damage is already difficult or costly to reverse.
Restarting Belgium’s shuttered reactors remains the fastest and cheapest way to get nuclear on the grid in Belgium. Two French EPR2 reactors, 3,300 MW of capacity, would cost an estimated €24 billion based on recent announcements from EDF. By contrast, bringing nearly 3,900 MW of existing Belgian reactors back to operating condition could cost as little as €3–4 billion. France is aiming for an estimated construction timeline of ten to eleven years for its domestic EPR2 reactors. Belgium, by contrast, could bring its first reactors back online within two years, and all of them within six. Restarts provide a near- to mid-term bridge to the government’s planned new nuclear construction, while also helping to build the supply chains, workforce, and sustained momentum needed to deliver those projects.
The economics of restarting Belgium's closed reactors are looking increasingly favorable against the cost of not restarting them. Tihange 1, the strongest restart candidate, could return to service within one to two years at a cost of approximately €350–500 million and produce power at roughly €65 per megawatt-hour (MWh). Iranian missile strikes on the world's largest LNG export facility have already pushed European gas prices above €60/MWh thermal before conversion to electricity which, at a combined-cycle efficiency of 55% and after accounting for the EU’s carbon tax, translates to an all-in electricity generation cost of approximately €140/MWh. Belgium’s newest and least-subsidised offshore wind facilities produce power at around €90/MWh; however, this excludes system integration, balancing, and backup capacity costs.
Electricity production from Belgium’s closed reactors could have a market value of €60 billion over twenty years. With ambitious targets for reindustrialization alongside the growth of high-performance computing and new energy-intensive industries, companies are willing to pay a premium for large amounts of reliable power. In one of the first deals to restart a previously closed nuclear plant in the United States, Microsoft agreed to pay between $110 and $115/MWh for power from Three Mile Island Unit 1 to enable its restart. If Belgium’s closed reactors were restarted and granted two ten-year life extensions each, at €100/MWh, they could generate roughly €60 billion in revenue from rapidly growing industries eager to meet their energy demands swiftly.
The majority of Belgians support the continued use of nuclear energy in Belgium. Radiant Energy Group’s 2025 global polling of nuclear attitudes found that 71% of Belgians favor extending the operation of existing nuclear reactors, with only 14% wanting to phase out nuclear in the country.
Introduction
Belgium’s Nuclear History
Throughout the late 20th and early 21st centuries, Belgium ranked among the top nuclear power producers per capita worldwide. Until recent closures, nuclear energy supplied over half of Belgium’s electricity—one of the highest shares globally. However, public opposition halted nuclear expansion by 1988, and in 2003, the government passed a law to phase out nuclear energy by 2025.
The Phaseout and Its Consequences
To replace nuclear power, Belgium planned to rely on a mix of wind, solar, and natural gas. In April 2021, the Council of Ministers authorized the construction of 2,300 MW of new gas- fired plants. However, this strategy faced a significant setback when Russia invaded Ukraine in 2022, disrupting cheap Russian gas imports to Europe. This crisis sparked public debates about extending nuclear plant operations. As a result, the government decided in March 2022 to extend the operation of two reactors, Doel 4 and Tihange 3, by ten years.
Despite the life extensions for Doel 4 and Tihange 3, the phaseout continued for the other five reactors. Doel 3 was permanently shut down on September 23, 2022, followed by Tihange 2 on January 31, 2023. Doel 1 was shut down on February 14, 2025; Tihange 1 on September 30, 2025; and Doel 2 on November 30, 2025.
The loss of five reactors has significantly weakened Belgium’s energy position. Before the closures, Belgium had been a net exporter of electricity. Now, Belgium is a net importer, relying on its neighbors for power. Ironically, a significant amount of this imported energy comes from France, where nuclear power provides roughly 70% of the electricity supply.
A New Political Direction
On January 31, 2025, a new pro-nuclear government was formed under Prime Minister Bart de Wever. The government’s platform included repealing the 2003 phaseout law; extending Doel 4 and Tihange 3 to 2045; joining the EU Nuclear Alliance; re-evaluating Belgian nuclear regulations to align with international standards; and exploring new nuclear builds. Energy Minister Mathieu Bihet outlined a target of 8 GW of nuclear capacity by 2035 by retaining 4 GW through life extensions while adding 4 GW of new build: “It's 4 gigawatts plus 4 gigawatts.”
On May 15, 2025, Belgium’s parliament voted 102 to 8, with 31 abstentions, to repeal the 2003 nuclear phaseout law, removing both the mandated closure dates and the ban on new nuclear construction. The new legislation opens the door to extending the lives of
shuttered reactors and engaging alternative operators if ENGIE declines. After clearing Tihange 3 for restart in July 2025 and Doel 4 in October 2025, Belgium’s nuclear regulator, FANC, explicitly called on the government to provide clarity on whether these reactors should operate beyond 2035, warning that “this time pressure poses a risk to the optimal preparation of nuclear installations.” FANC falls under the authority of the Minister of Interior rather than the Minister of Energy, creating a structural separation between the regulator overseeing nuclear operations and decommissioning and the minister responsible for energy policy. The head of FANC has previously stated that it is “exceptional, globally, for a reactor to be shut down after just forty years of service.”
Global and European Context
Belgium’s reversal reflects a broader global shift. Interest in nuclear energy is rising sharply, especially in countries that had recently closed or planned to close nuclear reactors for political reasons. In Sweden, the government has created financial tools for constructing new reactors and aims to add capacity equivalent to up to ten large-scale reactors by 2045. The Netherlands has more than tripled government funding for its nuclear program to support building at least four new reactors. Japan approved a new strategic energy plan to make "maximum use" of existing nuclear plants, and has extended reactor lifespans to sixty years. France repealed the law capping nuclear's share of electricity and removed the limit on reactor numbers, and has since announced plans to build six new large reactors with an option for eight more.
The renewed interest in nuclear has been driven in part by the energy crises of the last four years. Europe's pivot from nuclear towards natural gas assumed a stable, predictable LNG market. That assumption has not held. The 2022 energy crisis caused by Russia's invasion of Ukraine triggered the largest spike in fossil fuel prices since the 1970s oil shocks. The current conflict in Iran has reopened those same vulnerabilities. For countries that closed nuclear plants expecting cheap and reliable gas to fill the gap, the math has shifted. These back-to-back shocks have galvanized European nations and other countries to reduce their dependence on imported fossil fuels through the development of nuclear power.
This shift on nuclear also aligns with growing demand from high-performance computing, electrified transportation and heating, and other energy-intensive industries for clean baseload power. Microsoft’s landmark power purchase agreement for the Three Mile Island Unit 1 restart—valued at $16 billion over twenty years—set a new benchmark for nuclear economics. Meta announced a 1.1 GW, twenty-year nuclear power agreement at the Clinton plant in Illinois. Amazon said it will invest $20 billion in datacenter campuses in Pennsylvania powered by 1.9 GW of nuclear capacity from the Susquehanna plant. Google is pursuing both the restart of the Duane Arnold reactor and new SMR capacity from Kairos Power. Nucor, a major U.S. steel producer, signed a memorandum of understanding with a nuclear reactor vendor to help decarbonize its manufacturing processes.
Belgium’s nuclear reactors are well positioned to deliver domestic, reliable baseload power to help meet new demand, reducing dependence on volatile, expensive imported fossil fuels. Repairs and refurbishments cost less and come online faster than new builds. They also lay the groundwork for future nuclear expansion, rebuilding the workforce, restoring supply chains, and reviving the regulatory and industrial expertise that new nuclear construction will require.
In this report, Belgium’s recently-shuttered reactors have been reassessed, taking into account rising energy demand, nuclear restarts abroad, the repeal of the phaseout law, and the formation of a new pro-nuclear government. This report identifies the feasibility of restarting Belgium’s closed reactors and outlines the necessary steps to overcome current challenges.
Overview of Belgium's Nuclear Fleet
Belgium built seven nuclear reactors across two sites, Doel and Tihange, with the first entering service in 1975 and the last in 1985. At their peak, these reactors supplied over half the country’s electricity. Under the 2003 phaseout law, all seven were scheduled for closure by 2025. In March 2022, the government extended Doel 4 and Tihange 3 by ten years. The remaining five reactors were shut down between 2022 and 2025. Following the repeal of the phaseout law in May 2025, the government has signaled its intent to explore restarting shuttered units and extending the operating fleet beyond 2035.
Doel 4 and Tihange 3, Belgium’s two remaining operational reactors, completed their life-extension overhauls in 2025. Tihange 3 was cleared for restart in July and Doel 4 in October. The €1.6–€2 billion investment in upgrades is managed through a joint entity co-owned by ENGIE and the Belgian state under a contract-for-difference mechanism. Including ENGIE’s commission, these reactors produce power at approximately €90/MWh. FANC has publicly called for clarity on whether these reactors will operate beyond 2035—a decision the government has indicated it intends to pursue, with a target of extending their operational lives to 2045.
Engineering Readiness
Restart Assessments
Belgium’s five shuttered reactors fall into three restart classes based on feasibility, cost, and timeline. Restart Class 1 can return to service fastest at the lowest cost; Restart Class 3 involves the most extensive restoration.
Restart Class 1
Tihange 1 is the strongest restart candidate. It was the largest of Belgium’s older reactors and operated for fifty years before being disconnected from the grid on September 30, 2025. Its decommissioning is not scheduled until 2028, and full decommissioning is expected to last until 2040. The Belgian government asked ENGIE to avoid irreversible decommissioning steps while talks continue on a possible restart. Notably, as of publication, the demolition permit for two of the cooling towers has been suspended.
Given its recent shutdown and relatively limited decommissioning progress, Tihange 1 requires the least work and investment in order to return to operation. Most of the work involves basic part replacement, as well as work on the non-nuclear parts of the plant including replacement of cooling tower packing. Existing spent fuel, through a specific rearrangement of the reactor core, could allow the plant to operate for up to one year without needing to purchase new fuel. Tihange 1 could also operate at 50% power on one of its two turbines if grid capacity is constrained.
Restart Class 2
Doel 1 and Doel 2 are twin Westinghouse 2-Loop reactors that share a safety system. Both completed 50 years of service before shutting down in 2025 and are at relatively early stages of decommissioning, though Doel 1 is further along.
At Doel 2, chemical decontamination has not yet occurred, though it is planned for fall of 2026. Cable cutting has begun but is less advanced than at Doel 1. The main transformers have been drained of oil and moved to a storage yard on site to make space for a future waste treatment facility. Primary system reactor thimbles were cut as of the second week of February 2026. Disassembly of the turbine and generator has started, but secondary components are still in place.
At Doel 1, all fuel has been removed from the reactor building. Chemical cleaning by Framatome is scheduled for this May. The plant is undergoing mechanical dismantling of the turbine and generator, though the turbine could potentially be reassembled. Cutting of
electrical, heavy power, and control cables is underway. Primary system reactor thimbles have been cut. The machine hall has been emptied to make room for components from the primary containment system.
Restoring Doel 1 would be more involved than restarting Doel 2 given the further progression of decommissioning work. Under Belgium’s current WENRA-based regulations, the shared safety system would require restarting only one reactor. However, reactors of similar design and vintage with shared safety systems continue to operate safely elsewhere, including at Point Beach and Prairie Island in the United States and Beznau in Switzerland. Harmonizing Belgian regulations with international standards could allow both reactors to return to service.
Restart Class 3
Tihange 2 and Doel 3 have been shut down the longest and their decommissioning is the most advanced. Both have hydrogen flakes in their pressure vessels. FANC previously published a report, supported by Oak Ridge National Laboratory, concluding that these hydrogen flakes do not pose a significant safety concern.29 Tests on sample materials designed to mimic up to 70–100 years of reactor operation showed no signs of degradation or safety issues.
Tihange 2 is expected to receive its decommissioning license by the end of this year. The turbine hall has been largely stripped and components sold to Électricité de France (EDF), though they are reported to be in excellent condition and still available. The reactor’s
generators have been moved to Doel and would need to be replaced. The reactor vessel has undergone chemical decontamination. A study could be conducted to determine whether the chemical decontamination of the primary system caused any damage. Tihange 2 shares many design and operational similarities with Tihange 3, which has already received its life extension.
At Doel 3, decommissioning has advanced further than at any other shuttered reactor. The reactor vessel has undergone chemical decontamination. The secondary system machine hall is half empty. The turbine has had its components stripped and sold to EDF, though they are reported to still be in good condition and available. The condenser has been filled with concrete to immobilize it ahead of removal. Cables have been cut. Equipment from the reactor is being repurposed for Doel 4.
Financial Cost and Benefit Considerations
The financial case for restarting Belgium’s nuclear reactors is strong across the fleet. The table below summarizes estimated investments, timelines, and levelized costs for each reactor based on industry interviews conducted under the condition of anonymity, alongside the operating costs of the already-extended Doel 4 and Tihange 3.
These investment figures reflect the cost of returning each reactor to its prior operating condition under existing configurations. Notably, they exclude the costs associated with achieving compliance with updated regulatory requirements, as the government has elected to re-evaluate Belgian nuclear standards in alignment with international standards.
They also do not account for modernization. Future operators may choose to invest additional capital in digitized control systems, upgraded instrumentation, or other enhancements aimed at extending operational life and reducing long-term maintenance costs. Such investments would increase upfront costs but improve the long-term economics.
However, there is also a cost to not restarting reactors. Replacing lost nuclear capacity with gas, which as outlined above is trading at historic highs and could remain elevated for years given the extent of damage to Middle Eastern export infrastructure, would be expensive and pose significant risks to the country’s energy independence and security.
Replacing the lost power with renewables would also be costly and would leave Belgium more reliant on imported gas to ensure reliable power. Belgium's newest and least-subsidised offshore wind parks, built under the most competitive terms yet negotiated, produce power at an all-in cost of around €90/MWh. However, that figure excludes the system integration, balancing, and backup capacity costs. The effective cost rises significantly during periods of low wind when gas-fired peaking plants must fill the gap, particularly given current gas prices.
The costs of Belgian restarts are in line with other restart projects worldwide. Microsoft’s power purchase agreement for the restart of Three Mile Island Unit 1 was reportedly priced at $110–115/MWh over twenty years, higher than estimated costs for any Belgian reactor restart. At €100/MWh over the same period, Belgium’s five shuttered reactors could generate nearly €60 billion in revenue. The overall cost-effectiveness of restarts will depend heavily on the regulatory framework applied and the planned operating horizon.
Regulatory Considerations
WENRA, the Western European Nuclear Regulators Association, was established in 1999 to provide recommendations for regulating nuclear power plants in Europe. It issued safety recommendations in 2010 and 2014 aimed at harmonizing regulations across European countries. These recommendations exceeded existing regulations, including those currently enforced in France, the Netherlands, Switzerland, and the United States. Belgium was the only country that fully implemented WENRA recommendations into law.
Belgium's reactors already meet the safety standards applied in comparable EU member states. Harmonizing Belgium's regulatory requirements with those of its neighbors would allow life extensions to proceed in a relatively straightforward manner. Reactors would require an environmental impact assessment and safety and aging evaluations of all equipment. Then the necessary part repair and replacement could take place.
The costs of the Doel 4 and Tihange 3 life extensions, estimated at €1.6–€2 billion, were driven in large part by Belgium’s adoption of WENRA regulations. Restarting additional reactors under the same framework would be even more expensive. In the case of Doel 1 and 2, it would require only restarting one of the reactors due to their shared safety system. Reactors of similar design and vintage with shared safety systems continue to operate safely elsewhere, including Beznau Nuclear Power Plant in Switzerland and the Prairie Island and Point Beach nuclear power plants in the United States.
The new government has already committed to commissioning a comparative analysis of Belgian nuclear regulations against those of leading international regulators, including the U.S. NRC and France’s ASN. FANC has signaled its support for this process. Aligning Belgian standards with international best practice could significantly reduce restart costs while maintaining high safety standards.
Workforce
Thanks to the life extensions of Doel 4 and Tihange 3, as well as the recency of the nuclear closures, much of the experienced workforce is still available. Both sites employ around 1,000 people each.
To restart Belgium’s nuclear reactors, full staffing must be restored. This will require rehiring former staff, hiring new staff, and retraining existing staff to transition from decommissioning to recommissioning and operational tasks. Additional technicians and
craftsmen will be needed for repairs and restoration.
If Belgium’s government desires to quickly recommission reactors, decisions should be made quickly. Skilled operators, engineers, and technicians are already leaving for opportunities elsewhere, including at nuclear programs expanding in other countries. Acting promptly on restart decisions would allow Belgium to retain its existing workforce before it disperses.
If Tihange 1, Doel 1, and Doel 2 are not restarted, roughly 1,000 jobs will be lost after 2028. This would be a major loss for the nuclear sector, and would make any new nuclear development much more difficult in the future. These are technical, high-skill jobs that require time and training to replace. Maintaining existing expertise is a major advantage for future nuclear construction under consideration.
Fuel Supply
Nuclear fuel supply is not a limitation on restarts of Belgium’s nuclear reactors. Fuel fabricators typically require up to an eighteen-month turnaround for new fuel elements from the time of the order. In 2022, Westinghouse offered to supply fuel to German reactors within six months and has reaffirmed its ability to deliver fuel to German plants within a few months. If decisions are made quickly, new fuel can be turned around rapidly for Doel 2 and Tihange 1. Even following the standard fuel ordering timeline, fuel availability will not limit reactor readiness for Doel 1, Doel 3, and Tihange 2.
Waste Management
Restarting Belgium’s nuclear reactors would minimally impact the overall volume of nuclear waste to be managed. It is often stated that Belgium has the equivalent of seven Olympic-sized swimming pools of spent nuclear fuel to manage. This relatively small amount of waste is the byproduct of significant electricity generation over five decades of reactor operation.
If all of Belgium’s reactors were restarted, continued operation would add roughly 150 tonnes of spent fuel annually. Over a twenty-year period, this would increase the current spent fuel stock from around 4,000 tonnes to approximately 7,000 tonnes, roughly 40%
smaller than Germany's total spent fuel inventory from its nuclear power plants. Decommissioning the reactors does not eliminate the need to manage nuclear waste. Countries with active nuclear programs have taken the lead on waste management solutions, while countries without active reactors have fallen behind. For example, Finland has completed its deep geological repository and is testing its operations, while Sweden has issued a final construction permit for its repository. Potential energy remains within the spent fuel removed from reactors. This spent fuel can be recycled into Mixed Oxide fuel (MOX), which reactors in France currently use. Belgium could reduce its existing waste by reprocessing it and using it for fuel. It has done so before and could legally do so again. Alternatively, it could send spent fuel to France, which has an active reprocessing program. This would greatly reduce the final volume of any waste requiring disposal.
Public Acceptance
Recent polls show broad support for nuclear energy among Belgians. Radiant Energy Group’s global public opinion survey conducted in 2025 found that 40% of the Belgian public generally supports nuclear energy, while 25% opposes it. This level of support is similar to that of the U.S. and Canada, where reactors are being granted life extensions out to eighty years, and new reactors are under construction.
The poll also found that some respondents who were unsure or generally opposed to nuclear power still supported its continued use in Belgium. When asked if Belgium should keep using nuclear energy, 71% supported its continued use, and 46% supported building new plants, while only 14% favored phasing out and banning nuclear energy. Additionally, support for nuclear is strong among Belgians of all age groups, and Belgians are as supportive of nuclear as residents of countries with active building programs. The May 2025 parliamentary vote to repeal the phaseout law, passing 102 to 8, suggests this public sentiment is well-reflected in policymaking.
Next Steps
With swift action, Tihange 1 could be restarted within two years. Doel 1 and Doel 2 could follow shortly thereafter, coming back online as soon as 2028. The remaining three reactors could be brought back into operation by 2032.
To begin repair work, the Belgian government must find an owner and operator amenable to investing in the restarts. ENGIE has declared any extensions beyond Doel 4 and Tihange 3 "unthinkable,” a position Energy Minister Bihet called "unacceptable.“
In the meantime, the Belgian government should swiftly impose a moratorium on the decommissioning of its nuclear power plants. Each reactor should be carefully assessed to determine which components can be reused, which require repairs, and which need to be replaced entirely.
Conclusion
Restarting Belgium’s nuclear reactors is both feasible and practical. No insurmountable technical obstacles have been identified for any reactor in the fleet. Nuclear restarts offer the cheapest, fastest path to reliable, affordable power for Belgium, especially as the
ongoing global energy crisis drives up the cost and uncertainty of gas imports. Belgium has already demonstrated, through the Doel 4 and Tihange 3 life extensions, that its reactors can continue to operate reliably for years to come. Internationally, the United States is proving that bringing retired reactors back online is commercially viable.
With the phaseout law repealed and a pro-nuclear government in place, the political conditions for restarts have never been more favorable. However, the cost and time to restart grow as decommissioning continues to advance. The government should move to
halt all remaining decommissioning activities, commission formal restart assessments for each reactor beginning with Tihange 1, and secure binding agreements with ENGIE or alternative operators. Belgium has the reactors, the workforce, the grid connections, and the public support. What it needs now is speed.
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