EDF Energy owns and operates eight nuclear power stations in the UK (15 reactors) with a total capacity of 8.9GW (at 1 January 2021). Centrica plc. (Centrica) holds a 20% shareholding in Lake Acquisitions Limited, the parent company in which the nuclear generation assets sit (except Nuclear New Build).
On 7 June 2021 it was announced Dungeness would not return to service and would be moved to defueling operations with immediate effect. At Hunterston B, Reactor 3 ended power generation on 26 November 2021 as previously planned.
Total capacity at the end of the year was 7.8GW.
Seven of the eight nuclear power stations are AGR power stations (Dungeness B, Hartlepool, Heysham 1, Heysham 2, Hinkley Point B, Hunterston B and Torness) and the eighth, Sizewell B, is a Pressurised Water Reactor (PWR) power station.
Nuclear safety is EDF Energy’s overriding priority. In 2021, 7 events on the International Nuclear Event Scale (INES scale) were recorded, 6 of which were rated at Level 1 (anomaly) and 1 at Level 2 (incident) related to a loss of grid connection to the Heysham site.
EDF Energy operates to strict procedures to minimise and control the radiation doses received by employees and contractors at all of EDF Energy’s existing nuclear power stations. In 2021, the average individual dose received by all workers on EDF Energy’s existing nuclear sites was approximately 0.050mSv. The highest individual dose received in 2021 was 5.9mSv, with the legal dose limit being 20mSv per year.
The actual lifetime of each power station is determined primarily by the technical and economic practicability of supporting its safety case. This is assessed at each statutory outage for the following operating period through inspection, maintenance, testing and assessment of plant performance. Following the outage, consent is required from the Office for Nuclear regulation (ONR) before restarting the reactor. The operating period between statutory outages is normally three years for the AGR power stations and eighteen months for Sizewell B.
In addition, every ten years, the stations are subject to a more detailed and wide-ranging Periodic Safety Review (PSR) of design, operational and organisational safety which must also be accepted by the ONR in order to secure continued operation. The next PSR due for submission to ONR is in January 2024 for Sizewell B, with their decision expected in January 2025.
The AGR were designed with a nominal 25-year lifetime, and Sizewell B with a 40 year lifetime. However, with the aggregation of technical information, and operational and safety experience of EDF Energy, it has been possible to extend the expected AGR lifetimes. Since British Energy was acquired by EDF, the AGR lifetimes have been extended by an average of six years.
See also section 2.2.5 “Risks specific to nuclear activities” – Risk 5A “Nuclear plants in the United Kingdom”.
| Power Plant | Power (1) (in MW) | Output (2) (in TMh) | |
|---|---|---|---|
| AGR Power Plants | 2021 | 2020 | |
| Dungeness B | 1,090 | (0.2) | (0.2) |
| Hartlepool | 1,185 | 5.7 | 8,5 |
| Heysham 1 | 1,060 | 5.8 | 6,1 |
| Heysham 2 | 1,240 | 5.8 | 8.9 |
| Hinkley Point B | 965 | 4.8 | 1.8 |
| Hunterston B | 985 | 6.4 | 2.3 |
| Torness | 1,200 | 6.7 | 9.9 |
| PWR Power Plant | |||
| Sizewell B | 1,198 | 6.7 | 8.4 |
| TOTAL | 8,923 | 41.7 | 45.7 |
| LOAD FACTOR (3) | 59% | 58% | |
(1) Capacities are stated net of all power consumed for the power stations’ own use, including power imported from the grid at 1 January 2021. At 31 December 2021, Dungeness B and Hunterston B Reactor 3 had been moved to defuelling operations and the capacity of the generating reactors became 7,343MW.
(2) Output in each year reflects any refuelling, planned and unplanned outages. Dungeness B imports are excluded from the output from 1 December 2021.
(3) Load factors are obtained by dividing the actual output by the output that would have been achieved by each power plant operated at its stated capacity appropriate for the period. For 2021, Dungeness B has been included up to 31 March and Hunterston B Reactor 3 up to 30 September i.e. the end of the last quarter before end of generation, consistent with the WANO treatment of operational performance indicators.
The nuclear generation fleet produced 41.7TWh during 2021, 4.0TWh less than 2020 (45.7TWh). The reduction in output is largely due to:
