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Restart of Germany's Reactors: Can it be Done?

Germany can restart at least eight nuclear reactors, some within 9 months. Continuing the use of nuclear energy is supported by 67% of Germany and would stem losses in Germany’s industrial production. No insurmountable hurdles have been identified. However, pragmatism and proactiveness is required.

Executive summary

Germany shut down its last nuclear reactor on the 15th of April 2023. Since then energy prices have maintained higher than pre-energy crisis levels, Germany has started to be a net importer of electricity, and German industry has suffered with many factories moving to the US and other countries. Reverting the German nuclear shutdown is supported by the public, economical, and feasible.

67% of Germans still support nuclear energy after the closures of their power plants. Polling conducted by Civey on 11th of July 2023, after the closure of Germany’s last nuclear reactors, confirms that 2/3rds of the German public support the continued use of nuclear energy to achieve the EU's climate protection goals, a share over two times higher than the number of opposers to nuclear energy’s use.

€250 billion in German industry could benefit from cheaper wholesale electricity prices than in the US. As of May 2023, economic data shows deteriorating industrial output in Germany due to prohibitive energy costs. Restarting eight of Germany’s reactors could add over 85TWh of electricity annually at an operating cost of €25/MWh. 85TWh is 40% of the total German industrial electricity demand, or equivalent to the electricity demand of companies producing €250 billion GDP in Germany’s chemical, petrochemical, machinery, and equipment industries.

9 months, in a best-case scenario, would be needed to restart the majority of reactors. In our reasonable best-case scenario six reactors could be restarted within 9-12 months and the final two reactors restarted within 2-3 years. The main political bottleneck faced by the reactors would be the political amendment of the Atomic Energy Act. At most of the plants, the key time constraint would be the training of new operating personnel. For two of the reactors considered, repair, reconstruction, and approval of new operating licenses would take several years.

Other benefits Electricity CO2 emissions would fall by up to 80 million tonnes per year as coal generation is replaced by zero-emission nuclear generation. About 5,000 high-paying jobs would be retained in the rural areas hosting the nuclear plants. Additionally, a previously cutting-edge German nuclear technology industry would be revived as countries around the world start or expand their nuclear industries.


Germany once operated one of the world's largest nuclear power plant fleets. The country was also a leading provider of reactors and nuclear services. Decades of public opposition halted the expansion of nuclear energy by the time of reunification in 1990, followed by a phaseout agreement by 2002 to remove all reactors by the year 2022. In 2009, Angela Merkel’s governing coalition extended the operating times of all German nuclear plants by up to 14 years. Then, the accident at Fukushima Daiichi in Japan in March 2011 led Chancellor Merkel to back a fast phaseout to be completed by December 31st, 2022. Following a four-month delay due to energy shortages following Russia’s de facto natural gas pipeline embargo, Germany’s nuclear plants ceased electricity production on April 15th, 2023.

In the place of nuclear energy, Germany planned to keep its coal power plants, build large amounts of wind and solar power, and then mix in natural gas power to make up for daily and seasonal shifts in the energy coming from wind and solar. This mix of wind, solar, and natural gas would then gradually replace coal. Natural gas is not produced in Germany, and its cost on global markets is typically higher than German energy-intensive industries can bear. Germany’s way around this was to radically expand its gas pipelines to Russia to obtain the fuel for less than global market prices.

Russia’s full-scale invasion of Ukraine on February 24th, 2022, revealed the risk of relying on Russia for crucial energy supplies. Unfortunately, Germany had long planned its energy system and heavy industries around a peaceful future of inexpensive natural gas from pipelines and also purchased much of its oil and hard coal from Russia.

Germany had planned to import 110 billion cubic meters (BCM) of natural gas per year directly from Russia through the Nord Stream 1 and Nord Stream 2 pipelines. But in the days before the invasion, under intense political pressure, Germany cancelled the already-completed Nord Stream 2. By mid-July, Russia had sharply reduced gas flows on Nord Stream 1. Finally, 75% of Nord Stream’s carrying capacity was destroyed in an explosion on September 26, 2022.

The war and the disruption of gas supplies forced leading German politicians to publicly discuss the wisdom of the nuclear phaseout. On February 27th, 2022, the German Economy and Climate Minister Robert Habeck was asked by German broadcaster ARD whether he could imagine letting nuclear plants run longer than planned under Germany's exit plan. Habeck responded, “I would not reject it on ideological grounds.” Then, Lars Feld, chief advisor to German Finance Minister Christian Lindner of the Liberal coalition partner, said “Nuclear and coal must be back on the table.”

Indeed, the three political parties in Germany’s governing coalition did agree by late spring 2022 on reactivating coal plants. Nuclear power, in contrast, had become a polarizing issue for the cabinet, with leaders of the co-ruling Green Party most opposed to keeping the final three reactors. In the end, the government was forced to grant a nuclear operation extension in late 2022 for several months as a cold winter would’ve used up stored natural gas supplies across Europe.

Thus, Germany’s final reactors stopped producing electricity on 15th April 2023. Yet the German public has markedly warmed on nuclear power since the beginning of the crisis, and at least one plant operating company was openly supportive of life extension leading up to April 2023. Politicians have openly demanded a life extension, such as Minister-President of Bavaria Markus Söder advocating for Bavaria to keep its nuclear plants running in defiance of Federal policy. Green Party politician and longtime Heinrich Böll Stiftung executive board member Ralf Fücks publicly denounced the closures as wrong for the climate, the economy, and contrary to prevailing international direction.

E.On, one of the three German energy suppliers who last operated nuclear plants had been reportedly open to the idea and ready to discuss the possible extension of their plants. Only energy supplier RWE, which produces most of its power from coal and natural gas, made public statements against extensions.

The most immediate question for policymakers, the press, and the public alike is whether Germany’s nuclear reactors can be restored to operating condition for a return to electricity production.

The answer is Yes. There are eight key reactors able to be restarted at a reasonable cost and effort. This report identifies the obstacles to their restart and the required steps to overcome these obstacles.

The two most urgent actions are a halt to decommissioning activities and voting to amend the Atomic Energy Act.


Restart potential

Germany has eight nuclear reactors that are currently closed but where significant decommissioning of nuclear components has not yet started. These reactors have the most potential for being restarted. Together these reactors represent a cumulative 10.7 GW of electrical capacity, 30% of Germany’s 35 GW of annual minimum, or baseload, electricity demand.

All eight reactors can be restarted due to the preserved condition of their nuclear equipment, and especially their safety-essential systems. The ease with which this is possible is dependent on each reactor’s regional political support of nuclear power, the owner’s stance on life extensions, and the holding of an operating license.

Isar 2 has the most potential for being restarted given its location in a politically supportive region, being owned by operators in favor of life extensions, and currently still holding an operating license. Furthermore, the Isar 2 reactor is reported to have approximately 6 months of full power operation and 3 months of stretch operation left in its current fuel element, with Westinghouse reportedly capable of delivering new fuel elements within 6 months. Without any cause for concern about Isar 2’s fueling its timely restart can be de-risked and the financial cost of restart reduced.

Other reactors, including Grafenrehinfeld and Philippsburg 2, were surveyed in this analysis. Given their state of decommissioning, their location in anti-nuclear political regions, and their opposed ownership groups, their restart potential is assessed as lower than the eight reactors presented. These other reactors remain outstanding candidates for future repowering should political conditions change in Germany, indeed Philippsburg-2 is expected to be more readily refurbishable than Gundremmingen B, therefore we recommend a halt to any further destruction of plant equipment.


Restart feasibility

Restart is feasible. Eight German reactors are in physically outstanding condition and are younger than reactors now being life-extended around the world. For example, Emsland I and Isar II are 35 years old, having entered service in 1988. The other six reactors have operated for under 40 years. The median age of operating reactors in the USA is 43 years. Beznau Nuclear Plant in Aargau, Switzerland, six kilometers from German soil, hosts the oldest pressurized water reactors in the world, having operated for 54 years and counting. German reactors have already implemented upgrades and have conducted maintenance needed to continue operation for 50 years and beyond.

Operating conditions

By law, the six reactors still holding operating licenses as of July 2023 have to be maintained in operating condition. The two Gundremmingen reactors, currently without licenses and undergoing early stages of decommissioning, are still salvageable at greater cost and longer lead times.

For reactor decommissioning to start, plants must obtain a decommissioning license, called SAG (Stilllegungs- und Abbaugenehmigung) from the state (Bundesland) nuclear regulator in which they are sited. In a bid to reduce maintenance costs, all plant owners have applied for a SAG, although these decommissioning license applications can be withdrawn by operators at any time if they were to see value in maintaining their reactors.

Once applied for, state governments are able to influence and delay the SAG-licensing process. Krümmel, while shut down in 2011, has not been granted a decommissioning license due to objections by the state-level anti-nuclear Green Party environment minister due to complaints over technical issues. Ironically, anti-nuclear objections to decommissioning planning have meant Krümmel remains a candidate for being restarted. At Krümmel the turbo generator and some backup diesel generators have been removed but otherwise, the plant is in a pristine condition.

The two Gundremmingen reactors in Bavaria, while having their decommissioning licenses approved, have not yet experienced significant dismantling such that, according to industry officials, restart is feasible if decommissioning is paused by the operators. With anti-nuclear RWE as the operator of Gundremmingen, it would take some political pressure or financial leverage from the pro-nuclear Bavarian government to persuade RWE to withdraw its decommissioning license and reinstate its operating licenses.

One expert interviewee reports that Neckarwestheim II may require steam generator replacements, but only for operation past 2032. Steam generators are part of the pressurized water reactor’s design that turns water into steam. These German plants were designed to make steam generator replacement a routine, several-week operation by including purpose-built airlocks screwed into the containment walls. These airlocks can be unscrewed to reveal an opening large enough to move all major components through.

Sources report that both Brokdorf and Grohnde are revivable with timelines similar to those of the three most recently closed reactors. Experts agreed in principle with the July 2022 judgment of Joachim Bühler, executive board member of the TÜV, the German Technical Inspection Association, as reported in the mass-market "Bild" newspaper. Bühler said that closed reactors could return to service in a matter of months. Our experts expressed reservations about the shortest timelines stated by Bühler and believe that restart is limited by staff training and would thus take the majority of a year.

For long-term continued operation, other smaller components will have to be gradually replaced. However, these measures will not be urgent. All of these replacement costs should be self-financing through continued electricity sales.

Operating licenses

Before a life extension can be granted, the Atomic Energy Act must be amended. In 2011, legislators issued the 13th amendment to the act that prohibited the use of nuclear power for commercial electricity in Germany.

Like the Act itself, operating plans can be amended. As utility experts noted, experience with nuclear operation is greater than with decommissioning and dismantling. With the permission of the German Parliament, operators would need to provide proof that all upgrades and maintenance have been completed. With the Atomic Energy Act amended and with the necessary operation planning documents, operators would be able to apply to submit their request to the Nuclear Commission Authority for a life extension.

Workforce re-hiring

Even with the recent closures, plants are not allowed to substantially reduce staff in the first year after grid disconnection. As long as there is spent fuel onsite, a large complement of licensed staff is required to stay at the facility. All experts interviewed with knowledge of employee sentiment report the willingness of employees to return to active operation.

Plant personnel are prepared to replan their personal lives around enabling the continued operation of their respective power plants. Experts report that early retirement decisions and the onset of retirement age do not stand in the way of employees wishing to stay on in the case of plants being returned to service. In addition, operators expect to be able to look to other European nuclear programs for staffing needs as some workers have left the country in recent years in anticipation of closures. In the long term, utility managers say it takes around three years to train young engineers and technicians to be ready to take full responsibility for some key jobs in the plant.

Nuclear programs in France, Netherlands, Belgium, Switzerland, Sweden, and Czechia have recruited German nuclear experts as those experts have lost nuclear employment in Germany. Poland will likely draw on German nuclear employees as they begin their nuclear program in the next few years.

Fuel supply

The operating reactors have not ordered fuel for normal operations past December 2022. Nuclear fuel is carefully engineered for each specific reactor and is not generally interchangeable, although reactors fall into different classes with similar fuel in terms of shape or enrichment level. Brokdorf and Grohnde benefit from using the same fuel elements as Angra 2 in Brazil, speeding up fuel procurement. Isar 2 is an exception in having sufficient fuel on-site for 6-9 months of generation.

New fuel elements would have to be reordered from a fuel fabricating company like Westinghouse or Framatome. There is sufficient capacity in their facilities around the world to accommodate new orders. For example, fuel supplier Westinghouse’s Springfield (UK) factory is at significant under-capacity and has reduced the range of services it offers, but could restore services if Russian competitors remain barred from Western markets.

Fuel fabricators often work on an 18-month turnaround for the new fuel elements from the time of the order, matching the typical 18-month refueling cycle of most reactors. However, the CEO of the French nuclear fuel giant Orano has stated that they are ready and willing to work to find rapid solutions to continue operations.

Indeed, one expert has reported that Westinghouse only spends 114 days making each fuel shipment under normal conditions, counting the time after uranium material arrives at the fabrication facility. The facility plans to reduce these fabrication times to 57 days by 2025. Westinghouse is the manufacturer of Isar 2, Emsland, and Neckarwestheim fuel elements, These fuel elements are 18x18 grids that are only used by these three plants.

In the meantime, there are ways to extend fuel life in reactors during operation. As seen in Grafenrheinfeld, which closed in 2015, German operators have experience running reactors using fuel elements for longer service, up to or beyond two years before a refueling as a way to avoid fuel tax which is levied per new fuel assembly loaded into a reactor in Germany. By rearranging the fuel rods in the reactor, operators can optimize the fuel burn rate and keep the reactor safely operating on partial power.

This experience was in fact transferred to the currently operating reactors to keep them running for nearly four more months. At Brokdorf nuclear plant, enough fuel is available to start up and operate for at least a year using existing inventory and conservation procedures.

The Isar 2 reactor is reported to have approximately 6 months of full power operation and 3 months of stretch operation left in its current fuel element, with Westinghouse reportedly capable of delivering new fuel elements within 6 months.

Equipment validation

Supply chains for certain parts and equipment needed for long-term extension of operations have been moving out of Germany. Domestic suppliers will need to reorient their business strategy in the event of a term extension if a return to previous levels of equipment sourcing from German companies is desired. In the immediate term, it may be necessary to approach foreign manufacturers as early as possible. However, manufacturers are accustomed to producing custom parts and equipment for specific plants they take on as clients. In other parts of the world, supply chains have moved between entire countries depending on business conditions and political considerations. so this is not considered a deal-breaker or even unprecedented for the global industry.

In general, German steam generators are considered to have been manufactured with higher materials quality than those of American and French reactors. Replacement will be necessary only far into the future, if at all.

Waste disposal

According to the IAEA, each German reactor produces 25 tonnes of spent nuclear fuel waste each year. That means that restarted operation of the eight reactors in question would produce an additional 200 tonnes of spent fuel per year. If the eight reactors were to continue operation for 20 years, the amount of nuclear waste stored in Germany would grow from the current 11,000 tonnes to about 15,000 tonnes. This would be financially compensated by the extra decommissioning fund revenue produced by the continued operation.

Financial considerations

Restart costs for the six reactors with an operating license are estimated on the order of €100-200 million each. Equivalent to the potential profit of two months of operation, or equivalent to raising operating costs to approximately 25 €/MWh, four times lower than prevailing spot market rates.

Outside of this, the estimated marginal cost of continued operation is expected to be similar to historic costs, which are estimated to be in the range of 16.9-17.9 €/MWh. With inflation and higher fuel and service costs, 20-22 €/MWh is considered by experts to be a safe estimate for ongoing costs once one-time restart investments are made.

An estimate of the cost to extend the life of each reactor takes into account the unusual rush order for custom fuel, adjusting operating procedures to elongate the life of the current fuel, rehiring staff at short notice, and small necessary adjustments that may have been put off due to the approaching closure date. A reasonable estimate from an experienced senior manager put the cost of preparing for continued operation at €100-200 million each. This includes up to €50 million for the first batch of fuel. According to sources, no comprehensive accounting of costs has been done as of mid-Summer 2023 so these figures are necessarily estimates.

Restart costs for Gundremmingen B&C and Krümmel are more difficult to estimate. If major parts need replacement or repair after decommissioning work has already begun, “up to €1 billion” was a number obtained from one source. Turbine replacement costs at other Western reactors have cost in the several hundreds of millions of dollars for parts and labor.

To put this cost in perspective, at 2023 average spot electricity prices of 100 €/MWh, any of the 1.4GW reactors with an operating license would need to run for 1-2 months to make up the restart capital costs. Another way to put this cost in context is that if any of the 1.4GW reactors were extended for ten years at a cost of €150 million, this would add 1.40 €/MWh to current operating costs of about 21 €/MWh, or about 10% of total operating costs. By comparison, with July 2023 coal prices at 120 €/tonne and ETS emissions certificates at 84 €/tonne, hard coal power plants in Germany currently face marginal operation costs of €120 per MWh.

As an illustrated example, if one of these 1.4GW reactors were able to operate for a year at prevailing average wholesale costs of 100 €/MWh, annual profit before taxes on the order of €800 million would be achievable. A cold winter in 2024-2025, the first winter for which restarted reactors would be available if action is taken now, could lead to electricity prices significantly higher than this and thus make even a short life extension highly profitable for utilities on one hand, or produce a life-saving decline in electricity costs for industrial energy users on the other.

Public acceptance

In July 2023, after the closure of all of Germany’s nuclear power plants, 67% of German survey respondents were supportive of continuing the use of nuclear power to meet EU climate goals. Over two times more Germans are currently in support of nuclear power than in opposition, representing a major shift in German opinion versus Spring 2021 when a similar share of the public supported (49%) and opposed (42%) the use of nuclear power. Since Spring 2021, support for nuclear power’s use has risen across all major German political parties with the exception of the Greens where support having increased in Spring 2022 dropped again after the nuclear power plant closures.

Timelines and next steps

Five of the six German reactors with active licenses could be restarted 9 to 12 months after a withdrawal of their decommissioning license applications. Three more reactors could be restarted in 2-3 years.

The legal and statutory requirements would have to be met quickly to be able to continue using any of the nuclear power plants. Only a parliament member, political party, or the Federal Government may initiate a vote. When called upon, each political faction would elect a representative to speak on their behalf. For a revision or act to pass, there must be a majority within the parliament. Historically, these types of votes do take several months to come to a result.

The Federal Ministry of Economics and Technology can and should initiate a ban on decommissioning as quickly as possible through administrative channels. The Bundestag (federal parliament of Germany) would have to amend the Atomic Energy Act, in particular, paragraph 1, sentence 2ff; paragraphs 1a - 1d; paragraph 3, sentence 4ff in §7 AtG would have to be deleted.

Ideally, to assure operator cooperation, the Bundestag should pass a multiyear guarantee for the continued existence of the licensing requirements for nuclear power plants when amending the Atomic Energy Act. This would ensure that nuclear power plants could be licensed in principle; that operating licenses could only be withdrawn if operators were unreliable; and that operator investments in the plants would be recoverable over a longer period if electricity prices fall due to further declines in energy demand.



Restarting eight of Germany’s nuclear reactors is both possible and practicable. No insurmountable hurdles have been identified. Quick and consistent decisions at the political and administrative levels are needed. Most important is to enact a freeze of decommissioning activities at the power plants while awaiting amendments to the Atomic Energy Act. Utilities and industrial partners should then negotiate power purchase contracts that support the cost and timeline of restarts.



Full report downloads

Restart of Germanys Reactors. Can it be Done
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Wiederinbetriebnahme der deutschen Kernkraftwerke. Ist das machbar
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To compile this report, the authors interviewed board members and executives of nuclear-operating utilities and of nuclear technology companies, in addition to drawing from German-language publications and media. Interviewees provided details on the condition of anonymity on the challenges of life extension and restoration to service of the six reactors in question. Their responses were largely consistent and are referenced at various parts of the report.

AKEN (AktionskreisEnergie & Naturschutze.V.i.Gr.) is an independent action group focused on energy and nature conservation based in Frankfurt, Germany.

Radiant Energy Group is an independent consultancy based in Chicago, Illinois, USA.



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