CountryNuclear power in United Kingdom
United Kingdom has 9 reactors operating with 5,883 MW net installed capacity, 12.5 % of its electricity. 2 under construction. 36 shut down. First reactor connected in 1956.
United Kingdom ranks 12th among the 32 countries with operating reactors by net capacity, and 10th by number of reactors. Its first reactor, Calder Hall 1, started operating in 1956, 70 years ago. Its operating fleet comprises 8 GCR and 1 PWR. The highest-capacity plant in operation is Heysham, with 2,300 MW net, and the oldest unit still in service is Torness 1, operating since 1988. There are 2 units under construction at Hinkley Point.
GCR reactors in United Kingdom · FBR reactors in United Kingdom · PWR reactors in United Kingdom · SGHWR reactors in United Kingdom · Rankings
Electricity generation mix
Share of electricity generation, 2025 (closest earlier year; 2026 has no data) · Ember
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- Heysham 1, Reactor 1: Scheduled derate of 112 MW (18% of 610 MW) · operational reasons · effective October 24
- Hartlepool, reactor 1: back in service after 69 MW reduction · maintenance
- Hartlepool, Reactor 2: Planned 58 MW outage canceled or rescheduled (REMIT message withdrawn) · operational reasons
- Hartlepool, Reactor 2: Extended outage of 4 days (now scheduled to resume on October 30, 2026) · refueling
- Hartlepool, Reactor 2: Planned 58 MW outage canceled or rescheduled (REMIT message withdrawn) · operational reasons
Plants
| Plant | Units | Types | Status today | MWe operating |
|---|---|---|---|---|
| Heysham | 4 | GCR | 4 operating | 2,300 |
| Torness | 2 | GCR | 2 operating | 1,200 |
| Sizewell | 3 | PWR, GCR | operating2 shut down | 1,198 |
| Hartlepool | 2 | GCR | 2 operating | 1,185 |
| Berkeley | 2 | GCR | 2 shut down | — |
| Bradwell | 2 | GCR | 2 shut down | — |
| Calder Hall | 5 | GCR | 5 shut down | — |
| Chapelcross | 4 | GCR | 4 shut down | — |
| Dounreay | 2 | FBR | 2 shut down | — |
| Dungeness | 4 | GCR | 4 shut down | — |
| Hinkley Point | 6 | GCR, PWR | 2 under construction4 shut down | — |
| Hunterston | 4 | GCR | 4 shut down | — |
| Oldbury | 2 | GCR | 2 shut down | — |
| Trawsfynydd | 2 | GCR | 2 shut down | — |
| Winfrith SGHWR | 1 | SGHWR | shut down | — |
| Wylfa | 2 | GCR | 2 shut down | — |
Data: IAEA PRIS · Global Energy Monitor · Wikipedia · updated on Sep 17, 2026