Current state
| Status | Under construction |
| Design | EPR (PWR) |
| Net capacity | 1,630 MWe |
| Country | United Kingdom |
| Vendor | EDF/Framatome |
| Owner / operator | NNB Generation Company (EDF) |
| Construction start | 2018-12-11 |
| Original COD target | 2025 |
| Current COD estimate | 2030 |
| Schedule slippage | +5 years |
Britain's first new nuclear plant in a generation and the benchmark for Western large-reactor construction economics.
Notes
Flagship Western new-build and the canonical slippage story: 2030 start-up is five years past the original 2025 target. Unit 1 civils 94% by concrete volume at end-2025. Summer 2026: unit-1 fit-out accelerating per EDF video update; unit-2 vessel installed. ONR extended BYLOR improvement notices to Sep 14 2026 after a Jun formwork fall seriously injured a worker (INSite citing ONR) — regulatory watch item.
Milestone log
- 2018-12-11 — First nuclear concrete poured (official construction start) (source)
- 2024-01-23 — EDF announced revised schedule (Unit 1 2029-2031) and cost range £31-35bn (2015 money) (source)
- 2026-01-20 — All 24 primary loop welds completed on Unit 1 (source)
- 2026-03-02 — Unit 1 start-up pushed to 2030 on M&E productivity shortfall; cost estimate £35bn (2015 money) (source)
The milestone log is append-only: corrections are recorded as new entries, never rewrites. Full history via /api/v1/changes.