Mr Baldwin will be expected to play a key role in the development of the body regulating the nuclear power industry.
Announcing the creation of the ONR in February, the Coalition government said the new body would consolidate civil nuclear and radioactive transport safety and security regulation in one place. It will take over functions currently carried out by the Health and Safety Executive and the Department for Transport.
Perth-based SSE has ambitions to move into nuclear generation.
“We believe that participating in new nuclear power stations could help to deliver on our commitments to maintaining a diverse generation portfolio, helping us to provide the energy people need in a reliable and sustainable way,” says SSE on its website.
The group has announced plans to build a new reactor at Sellafield in Cumbria with GDF Suez of France and Iberdrola of Spain.
The consortium hopes to begin construction of the first new reactor around 2014. It does not expect the plant to be commissioned before 2020.
A former chief executive of Powergen, Mr Baldwin became a non-executive director of SSE in 2006.