Sizewell nuclear power plant A1
Gross capacity
245MW
Sizewell nuclear power plant A1 is a gas-cooled reactor unit at Sizewell nuclear power plant in United Kingdom rated at 245 MW gross. It is retired. Commercial operation began 25 Mar 1966.
Specification
| Reactor type | Gas-cooled reactor (GCR) |
|---|---|
| Model | MAGNOX |
| Size | Small300 MWe or less |
| Coolant | Carbon dioxide |
| Moderator | Graphite |
| Gross capacity | 245MW |
| Net capacity (reference) | 210MW |
| Net capacity (design) | 290MW |
| Thermal output | 1,010MWt |
| NSSS vendor | not on record |
| Typical enrichment | Natural uranium to 2.5–3.5% U-235 |
Ownership & location
| Site | Sizewell nuclear power plant |
|---|---|
| Unit | A1 |
| Country | United Kingdom |
| Owner | Nuclear Decommissioning Authority (United Kingdom)100% |
| Operator | Magnox |
| Coordinates | 52.2123, 1.6195 |
Fuel chain for this unit
Fuel form
Uranium metal (Magnox) or uranium dioxide (AGR)
Enrichment
Natural uranium to 2.5–3.5% U-235 no enrichment required
Upstream
This unit runs on natural uranium, so its fuel chain has no enrichment step at all: mine → mill → conversion → fabrication. That is the shortest fuel chain of any commercial reactor type, and it makes the operator independent of the four organisations that control enrichment worldwide.
Fabricator capability is recorded against reactor type and model line, not against named units,
utilities do not publish fuel contracts. See the fuel chain.
Timeline
- 1 Apr 1961Construction start
- 1 Jun 1965First criticality
- 21 Jan 1966Grid connection
- 25 Mar 1966Commercial operation
- 31 Dec 2006Permanent shutdown
Other units at Sizewell nuclear power plant
| Unit | Status | Gross MW |
|---|---|---|
| Sizewell nuclear power plant A2 | Retired | 245 |
| Sizewell nuclear power plant B | 1,250 | |
| Sizewell nuclear power plant C1 | Pre-construction | 1,600 |
| Sizewell nuclear power plant C2 | Pre-construction | 1,600 |
Other MAGNOX units
30 units worldwide share this model designation.
| Unit | Country | Status | Gross MW |
|---|---|---|---|
| Nyongbyon nuclear power plant 1 | North Korea | 5 | |
| Berkeley nuclear power plant 1 | United Kingdom | Retired | 166 |
| Berkeley nuclear power plant 2 | United Kingdom | Retired | 166 |
| Bradwell nuclear power plant 1 | United Kingdom | Retired | 146 |
| Bradwell nuclear power plant 2 | United Kingdom | Retired | 146 |
| Calder Hall nuclear power plant 1 | United Kingdom | Retired | 60 |
| Calder Hall nuclear power plant 2 | United Kingdom | Retired | 60 |
| Calder Hall nuclear power plant 3 | United Kingdom | Retired | 60 |
| Calder Hall nuclear power plant 4 | United Kingdom | Retired | 60 |
| Chapelcross nuclear power plant 1 | United Kingdom | Retired | 60 |
| Chapelcross nuclear power plant 2 | United Kingdom | Retired | 60 |
| Chapelcross nuclear power plant 3 | United Kingdom | Retired | 60 |
Sources
- Global Nuclear Power Tracker, Global Energy Monitor, August 2026 release , CC BY 4.0 · retrieved 2026-09-06 · this unit last researched by GEM on 2024-05-17
- GEM.wiki entry (further reading) , CC BY-SA 4.0, linked, not quoted
How these sources are used, including the corrections applied on top of them and what is deliberately left blank · download the underlying data