Ten years ago, France alone generated more than half of Europe's nuclear electricity, and Germany's reactors still hummed. Since then, shutdowns in the west have collided with quiet expansion in the east, and a continent once defined by a single atomic giant now looks stranger, flatter, and more unevenly lit.
France burned brightly, a nuclear near-monopoly producing 437 TWh — more than the next six European countries combined. To its north and east lay a quieter archipelago of reactors: Germany, Sweden, Belgium, the Czechia, each supplying a quarter to a third of their national grids.
The rest of the EU — Italy, Poland, Ireland, Austria — sat out. A continent agreed on climate goals but disagreed, profoundly, on how to get there.
Between 2015 and 2023, Germany's nuclear output fell from 91.8 TWh to 6.7 — and then, on 15 April 2023, to zero. The last three reactors — Isar 2, Neckarwestheim 2, Emsland — were disconnected on a single Saturday evening.
France, meanwhile, had troubles of its own: stress corrosion cracks across the fleet sent 2022 output to a 35-year low of 294 TWh. For a brief moment the continent's largest producer was also its most fragile.
Finland's new reactor, Olkiluoto 3, came online at full capacity. Slovakia added Mochovce 3. Czechia and Bulgaria held steady. The share of EU nuclear output flowing from east of the Rhine rose from 17% in 2015 to 29% a decade later.
France still leads — and by some distance. But the margin is narrower, and the assumptions thinner, than at any point since the fleet was built.
Switch the metric to kilowatt-hours per person and a different country climbs to the top: Slovakia, whose small population and steady fleet put it ahead of both France and Sweden. Finland, after Olkiluoto 3 came online, follows close behind.
Per-capita framing is not merely cosmetic. It reveals which societies have chosen, per household, to depend on fission — and which have not.
Here France remains untouchable, with roughly 70% of domestic electricity coming from nuclear in a typical year. Slovakia and Hungary follow above 50%. A handful of countries — Belgium, Czechia, Finland, Slovenia, Bulgaria — cluster near 40%.
Everyone else, including Europe's largest economies after France, sits below 10%.
Each card below traces one country's nuclear output from 2015 to 2025. The shape of the line says more than the number: Germany's cliff, Finland's climb, France's 2022 dip, Spain's long, slow tilt downward.
A wave of small modular reactors is at least theoretically on the way; Poland has committed to a conventional fleet and broken ground near Choczewo. France has pledged six new EPR2 reactors, with options for eight more. Belgium, which once set a 2025 exit date, has quietly extended two of its reactors through 2035.
Whether Europe's nuclear output in 2035 is higher or lower than today is genuinely undecided — the steepest decisions lie not with engineers but with ministries. What is certain is that the map will look different again. It has always looked different again.
— Visualization by The Calipso Review Data Desk. All figures rounded.