Trawsfynydd nuclear power plant 1
Retired United Kingdom
Gross capacity
235MW
Trawsfynydd nuclear power plant 1 is a gas-cooled reactor unit at Trawsfynydd nuclear power plant in United Kingdom rated at 235 MW gross. It is retired. Commercial operation began 24 Mar 1965.
Specification
| Reactor type | Gas-cooled reactor (GCR) |
|---|---|
| Model | MAGNOX |
| Size class | Large |
| Coolant | Carbon dioxide |
| Moderator | Graphite |
| Gross capacity | 235MW |
| Net capacity (reference) | 195MW |
| Net capacity (design) | 250MW |
| Thermal output | 850MWt |
| Typical enrichment | Natural uranium to 2.5–3.5% U-235 |
Ownership & location
| Site | Trawsfynydd nuclear power plant |
|---|---|
| Unit | 1 |
| Country | United Kingdom |
| Owner | Nuclear Decommissioning Authority (United Kingdom)100% |
| Operator | Magnox |
| Coordinates | 52.9252, -3.9474 |
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utilities do not publish fuel contracts.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 Jul 1959Construction start
- 1 Sep 1964First criticality
- 14 Jan 1965Grid connection
- 24 Mar 1965Commercial operation
- 6 Feb 1991Permanent shutdown
Other units at Trawsfynydd nuclear power plant
| Unit | Status | Gross MW |
|---|---|---|
| Trawsfynydd nuclear power plant 2 | Retired | 235 |
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