Wider location
This view places the station in its surrounding district, coast or industrial corridor.
Approx. coordinate used: 50.6818, -2.2677
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Nuclear Restoration Services
NUCLEAR Β· Decommissioning
Winfrith SGHWR
The Steam Generating Heavy Water Reactor at Winfrith was a 100 MW prototype that supplied electricity to the national grid while testing a pressure-tube, heavy-water-moderated reactor concept.
Steam Generating Heavy Water Reactor
Dorset
England
Commissioned 1967 Closed 1990
Nuclear Restoration Services
Site image
Decommissioning
A licensed station photograph is not yet attached to this record. The panel shows an indicative plant-form view until a site image is added.
Steam Generating Heavy Water Reactor
Technical views
Simplified SGHWR sequence showing heavy-water moderation, light-water coolant pressure tubes, steam production, turbine generation and condensation.
Station map context
OpenStreetMap view showing the actual atlas coordinate for Winfrith SGHWR, with a wider local view and a closer site-focused view.
Closer site view
This tighter map makes the specific site position much clearer for the station record.
Marker placed on the stored station coordinate in the atlas dataset.
Reference snapshot
StatusDecommissioning
FuelNuclear
TechnologySteam Generating Heavy Water Reactor
Capacity100 MW
Commissioned1967
Closed1990
RegionDorset
NationEngland
OwnerNuclear Decommissioning Authority
OperatorNuclear Restoration Services
Why it matters
- 100 MW experimental grid-generating reactor
- Heavy-water moderator and light-water coolant
- Winfrith research site now being restored
This summary focuses on the key facts that explain the stationβs role in the wider UK generation system.
Station timeline
These timeline entries highlight the main milestones for the site, including commissioning, major changes, closure and current status where relevant.
SGHWR entered service as a prototype power reactor and supplied electricity to the national grid.
The SGHWR ended operation after more than two decades of research and electricity generation.
NRS continued regulatory and engineering work for dismantling and restoring the remaining Winfrith reactor areas.
Reading the landscape
Power-station siting reflects engineering requirements, fuel and water logistics, grid access, industrial geography and the planning frameworks of the period in which the site was developed. Winfrith SGHWR should therefore be read as part of a wider infrastructure system rather than as an isolated structure in the landscape.
Approx. coordinates: 50.6818, -2.2677
Source notes
- NRS and Environment Agency Winfrith documents describe SGHWR as a 100 MW reactor that supplied electricity to the national grid.
- The atlas includes SGHWR because it was a genuine grid-generating prototype, while non-generating research reactors are outside the core station list.
- Sources reviewed July 2026.
Gallery notes
These notes highlight the main structures, layout characteristics and historic changes associated with the station. They are intended as a concise interpretive layer alongside the reference data, timeline and technical diagrams.
Pressure-tube concept
SGHWR used pressure tubes, heavy-water moderation and light-water cooling, distinguishing it from Britainβs commercial gas-cooled reactors.
Research and generation
Winfrith combined experimental reactor development with useful electricity production for the public grid.
Site restoration
The remaining SGHWR and Dragon reactor areas form the centre of the modern Winfrith end-state programme.
Related stations
Further record development
This record can be expanded further with licensed site plans, archival photography, demolition or redevelopment updates, fuller unit-level timelines and linked planning or environmental documentation.