- Babcock Marine
- Babcock Support Services Ltd
- BAE Systems (Operations) Ltd
- Bendalls Engineering
- British Energy Generation Ltd
- BSL Limited
- CIBA Speciality Chemicals
- DET Norske Veritas BV
- DML Devonport
- KAT Nuclear
- LLW Repository
- Langley Holdings PLC
- Magnox North / Magnox South
- Ministry of Defence
- MAES IPT
- Mitsui Babcock
- NIS Limited
- NNC Limited
- Rolls Laval
- Rolls Royce Fuel Cell Systems
- Rolls Royce Combustion
- Rolls Royce Power Engineering
- RTS Advanced Robotics Ltd
- Sellafield Limited
- Taywood Engineering Limited
- Tiger Marine
- UKAEA
- Vosper Thorneycroft (UK) Ltd
