Data and methodology
Nuclear outage data
The homepage figure summarizes three years of energy lost during equipment-related, unplanned full outages reported to the IAEA Power Reactor Information System (PRIS).
Reported energy lost by year
IAEA Nuclear Power Reactors in the World, Table 20: Direct causes of full outages. Plant equipment problem/failure, Unplanned Full Outages, Energy Lost (GWh).
| Year | Energy lost | IAEA source |
|---|---|---|
| 2023 | 94,537 GWh(94.5 TWh) | 2024 edition · Table 20 |
| 2024 | 68,695 GWh(68.7 TWh) | 2025 edition · Table 20 |
| 2025 | 51,930 GWh(51.9 TWh) | 2026 edition · Table 20 |
Calculation
(94,537 + 68,695 + 51,930) GWh ÷ 3 = 71,720.7 GWh/year, or 71.7 TWh/year rounded to one decimal place.
Scope and limits
The IAEA figures cover reactors that had achieved full commercial operation by each reporting year. They count energy lost during unplanned full outages attributed to plant equipment problems or failures. Planned outages, partial power reductions, and other unplanned outage causes are outside this calculation.
PRIS data are submitted by Member States and plant data providers. The IAEA's 2026 edition says operating experience data for Ukrainian reactors in 2022–2025 were not reported by publication. Reporting coverage and the reactor population can differ by year, so these figures do not establish a like-for-like trend.
This arithmetic average provides industry context. It does not measure an effect of Metroscope software.