Nuclear output in France

September 2024 September 2025 Change
Output of the month 27.4TWh 28.9TWh 5.5%
Cumulative output 262.1TWh 268.9TWh 2.6%

Nuclear output in September 2025 amounted to 28.9TWh, up by 1.5TWh vs September 2024.

Since the beginning of the year, cumulative annual output was 268.9 TWh, up by 6.8TWh compared to 2024. This is explained by the good availability of the reactors in operation, well managed outages and still a strong modulation.

Evolution of cumulative nuclear output in France in September 2025 (description bellow)

Nuclear output in the United Kingdom

September 2024 September 2025 Change
Output of the month 3.3TWh 1.7TWh -48.7%
Cumulative output 28.5TWh 25.3TWh -11.2%

Nuclear output in September was 1.7TWh, down 1.6TWh vs September 2024.

Cumulative output was 25.3TWh, 3.2TWh lower than prior year. Steam valve incidents impacted the output at Hartlepool and Heysham 1 in 2024, whereas an important maintenance programme and outages occured in 2025.

Evolution of cumulative nuclear output in UK in September 2025 (description bellow)