DIDO
DIDO, a research reactor (heavy water) in Harwell, United Kingdom, with 26 MW of thermal power, operated by Atomic Energy Research Establishment. Shut down, first critical in 1956.
It was one of the 46 research reactors the United Kingdom has had; 1 remains in operation today. It went critical 9 years after the first research reactor in the United Kingdom, GLEEP (1947). 10 heavy-water research reactors remain in operation today across 7 countries. Its declared uses include innovative research and materials testing.
- Country
- United Kingdom
- City
- Harwell
- Type
- Heavy water
- Thermal power
- 26 MW
- Operator
- Atomic Energy Research Establishment
- Status
- Shut down
- First criticality
- 1956
- Purpose
- Innovative research, materials testing
See also: every research reactor in United Kingdom · How research reactors work
Data: IAEA RRDB · updated on Sep 3, 2026