Winfrith

Winfrith lies on Winfrith Heath in Dorset, a flat stretch of land between the A352 road and the South West Main Line. The Atomic Energy Establishment opened here in 1960 to test many new nuclear reactor designs. John Cockcroft, head of the Research Group, pushed for a site with space for several experimental reactors. Christopher Hinton, leading the Industrial Group, preferred to focus on one design, but Cockcroft’s plan won. The government passed the Winfrith Heath Act 1957 to clear rights of common and allow construction to begin. By 1959 the first low-energy reactor, ZENITH, was running, and a five-mile pipeline carried cooling water to the sea at Arish Mell. The site became home to a dozen reactors, each built for a different purpose. NESTOR produced neutrons for reactor design studies, while DIMPLE examined heavy water systems. ZEBRA studied plutonium fuel assemblies and HECTOR tested materials for power plants. The Dragon reactor, a European project, ran as the first high-temperature gas-cooled reactor in Britain. Staff numbers grew to 2,350 by 1966 before the programme began to wind down. The largest reactor, SGHWR, supplied up to 100 MW to the National Grid from 1967 until its closure in 1990. Today the site is divided between the licensed nuclear area, Dorset Innovation Park and Dorset Police headquarters. The Nuclear Decommissioning Authority manages the remaining reactors and waste facilities. Old reactor buildings stand alongside new business units, while decommissioning work continues under public consultation. The heathland around the site remains open, offering quiet walks past the remnants of scientific ambition.