On behalf of 12,000 professional workers in the industry, General Secretary Paul Noon said: "The Government has recognised the need for speed and openness in clarifying exactly what happened. For the sake of the families that is vitally important. Michael Redfern is an excellent choice because of his experience of the Alder Hey inquiry but we still need to see the terms of reference."

Noon stressed that the inquiry should be tightly focused on those cases that have already come to light at BNFL Sellafield rather than turned into an all-encompassing review of medical procedures in different public organisations over a 30-year period.

"When this inquiry has reported, then in the light of its findings we can judge whether a wider inquiry is needed.

"Meanwhile the company should be informing relatives as quickly as possible and there should be no hold-up in that process because of the inquiry. That is the only way to reassure families who fear their relatives might have been involved as well as those who were."

At the request of the Sellafield trade unions, British Nuclear Fuels will tomorrow set up a helpline to give advice and information for the families of any worker who may have potentially been affected.