Nuclear power plant in Gwynedd, United Kingdom. Approximate location 52.9252, -3.9474.
NuclearGwyneddUnited KingdomMAGNOXgas-cooled reactor
Trawsfynydd nuclear power plant is a 470 MW nuclear power station in Gwynedd, United Kingdom. It is operated by Nuclear Decommissioning Authority (United Kingdom) [100%]. Based on its capacity (estimated), it can supply roughly 1.1 million homes (estimated). It ranks #88 of 2,860 United Kingdom power plants by installed capacity. Commissioned in 1965, it is around 61 years old — an older, legacy facility. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, nuclear supplies about 12.4% of United Kingdom's electricity; the national grid averages 217 gCO₂/kWh (64.4% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id GEM_nuc_trawsfynydd_unite.
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
The capacity and fuel fields on this page are source-record values from the upstream open dataset. They are useful for identification and ranking, but they have not been upgraded to a 2026 registry/GEM-location verified value.
capacity: GEM GNPT; fuel: GEM GNPT
At 470 MW, Trawsfynydd nuclear power plant is below the median nuclear plant in United Kingdom (965 MW). Technically it is described as gas-cooled reactor. Nuclear plants split uranium to raise steam with no direct CO₂; they run as steady baseload with very high capacity factors and the longest operating lifetimes of any thermal plant.
Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.
Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).
Operated by Nuclear Decommissioning Authority (United Kingdom) [100%].
This nuclear plant uses heat from nuclear fission to raise steam for a turbine-generator. It sits in a temperate oceanic climate (Köppen Cfb) — Northern Hemisphere, latitude 52.9°N — which shapes how much energy it can produce and how its output varies through the year.
Climate zone & typical temperatures: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid).
For a plant’s outdoor hardware — heat-recovery steam generators (HRSG), expansion joints, valves, flanges and their insulation — the local climate sets how fast unprotected steel and coatings degrade. This site sits in a corrosive environment (estimated ISO 9223 class C4 — High), with humidity / wetness the leading environmental stress.
Higher environmental severity is exactly where protective removable insulation pays back most: a sheltered micro-climate slows corrosion, UV and thermal-cycling damage and extends outdoor hardware service life. This is an indicative site-climate context — not a condition assessment of any specific plant or operator.
Indicative estimate via the ISO 9223:2012 informative method (atmospheric corrosivity from temperature, time-of-wetness and airborne salinity), using WorldClim climate normals, the Köppen-Geiger class and coast distance. Indicative, not a measured corrosion rate.
The #18 largest nuclear power plant of 25 in United Kingdom by capacity.
United Kingdom has 25 nuclear power plants in this dataset, together about 27,683 MW of capacity.
Coordinates 52.9252, -3.9474 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Trawsfynydd nuclear power plant is a 470 MW nuclear power plant in Gwynedd, United Kingdom, commissioned in 1965.
Its output is enough to supply roughly 1,058,708 homes (estimated).
Trawsfynydd nuclear power plant is operated by Nuclear Decommissioning Authority (United Kingdom) [100%].
