The new authority will avoid differing standards of accounting and will improve coordination. It will also allow BNFL greater financial clarity to continue its efforts to re-build customer confidence and future business.

"This announcement starts to address the issue of accountability and helps give greater transparency to managing the UK’s nuclear legacy," said Dai Hudd, national officer representing 5,000 Prospect members at BNFL. "It is important that the proposed LMA is given the funds and expertise to do its job effectively. It also allows BNFL to concentrate its plans for future investment and the growth of its business."

A key part of the announcement concerns the future of BNFL and the Sellafield site which, it makes clear, will continue to be managed as a single organisation.

Jack Dromey, national secretary for the Transport and General Workers’ Union, said: "There is much that has been done at Sellafield, but there is still more to do. This announcement allows BNFL to continue to recover and to build a secure future as an integrated company."

The unions are particularly keen to ensure that existing expertise is not lost in the setting up of the LMA. In particular, the new authority must use the skills and knowledge in existing organisations such as BNFL, UKAEA and NIREX.

John Billard, Prospect national officer, said: "There is a wealth of skill here. However, we would not agree to a break-up of management at site level, particularly where both UKAEA and BNFL have established control of nuclear decommissioning."

Unions will be scrutinising the detail of the White Paper but in the meantime welcome ministerial assurances given previously to their members.