France’s day-ahead power prices surged by as much as 21.8% to $164.39 per megawatt hour as intense heatwaves forced severe cuts to nuclear generation across Europe. Meanwhile, energy researchers point to historical Swedish 1970s construction models as a potential blueprint to curb rising future nuclear building costs.
Heatwaves Curb European Nuclear Power and Send Prices Soaring
Europe’s largest nuclear electricity supplier faced mounting strain as a fresh heatwave forced significant reductions in generation capacity. France saw day-ahead power prices soar by as much as 21.8% to $164.39 (142.5 euros) per megawatt hour (MWh) on Tuesday morning local time, according to data from LSEG cited by Reuters.
Data published by nuclear plant operator EDF indicated that French nuclear generation would drop by 7.3 gigawatts (GW) on Wednesday. That reduction accounts for 12% of the country’s total nuclear capacity amid at least the fifth extremely hot wave to grip France since June. Nuclear energy typically supplies about 70% of the French electricity mix, leaving the grid acutely sensitive to high ambient temperatures.
The underlying operational constraint centers on cooling systems. As river water levels run low and temperatures climb due to the prolonged and intense heatwaves, power plants face strict limitations on using that water for cooling reactors. Additional upward pressure on prices stems from a surge in power consumption as residents turn on cooling systems across the country.
The climate pressure extended far beyond French borders. In central and eastern Europe, Hungary and Romania faced severe disruptions after the Danube River dropped to its lowest water level in 90 years, forcing reactors offline at their respective sole nuclear facilities. Hungary brought a turbine at the Paks nuclear plant back online on Monday following rainfall in Austria. Romania resorted to blasting a rock formation and sinking barges loaded with rocks to deviate the Danube’s flow and maintain adequate cooling water at the Cernavoda nuclear plant.
Historical Swedish Reactor Builds As a Cost Blueprint
While continental operators battle immediate climate disruptions, energy economists and researchers are looking backward to reevaluate how new atomic plants can be built affordably. Jonas Kristiansen Nøland, a professor of energy conversion at NTNU, argued in a debattartikel published in Affärsvärlden that Sweden’s historical nuclear program demonstrates how new reactors can be constructed significantly cheaper than current official cost estimates suggest.
Nøland referenced findings from economics professor Magnus Henrekson and environmental economist Mats Nilsson. Their study in Ekonomisk Debatt concluded that policy frameworks, institutional conditions, and standardized models heavily dictate nuclear expenses. According to their research, stabile regulatory frameworks and recurring orders could reduce production costs by 30 to 50 percent.
Expanding on those findings, Nøland examined historical data covering 349 international reactors built during the 1970s and 1980s. He noted that Sweden’s 12 nuclear reactors ranked among the cheapest 5 to 10 percent built globally. Adjusted to June 2026 monetary values, those Swedish plants cost roughly one-sixth of the figures currently used in state inquiries regarding financing and risk-sharing for new nuclear developments.
Illustrative Calculations Versus Proposed Financing Models
Applying those historical construction benchmarks yields an illustrative production cost of around 30 öre per kilowatt-hour, according to Nøland’s calculations. That figure stands in sharp contrast to the proposed contract price of 80 öre per kilowatt-hour over 40 years outlined in current Swedish financing proposals.
Researchers emphasize that the 30 öre figure is an analytical benchmark rather than a commercial vendor offer. Early Swedish boiling water reactors were developed directly by ASEA without licensing from American firm GE. Oskarshamn 1 served as the country’s first commercial plant with a 440-megawatt capacity, featuring simpler systems and fewer major components that contributed to strong economic advantages.
Nøland highlighted Barsebäck 1 and 2, which each featured an installed capacity of 580 megawatts, as among the most economical units in the national program. Nordic Baseload Power has applied for state support to develop new nuclear power at Barsebäck utilizing two boiling water reactors, though no final investment or construction decision has been made. Vattenfall is evaluating Rolls-Royce SMR reactors rated at 470 megawatts for its planned expansion, though technology selection does not constitute a formal equipment order.
Industry Structure and the Cost of Lost Experience
A major driver of modern nuclear expense involves indirect or soft costs. Citing a study published in the journal Joule, Nøland pointed out that 72 percent of cost increases for American nuclear projects between 1976 and 1987 stemmed from indirect and soft costs rather than physical reactor hardware. The OECD Nuclear Energy Agency has similarly cited weakened supply chains and lost construction experience as primary culprits behind high modern budgets.
To capture historical cost efficiencies, Nøland advocates for organizing future nuclear projects as a cohesive, long-term industrial program rather than isolated builds. His recommendations include freezing design specifications before construction begins, establishing coordinated permit reviews with binding deadlines, and implementing type approvals for reactor series so that approved designs bypass redundant regulatory reviews at new sites.
