Hewitt said the LMA will be responsible for developing a national decommissioning strategy.

"The work required to deal with the legacy (of Britain's nuclear involvement) extends decades into the future and the costs involved are inherently uncertain," she said, adding the cost will be about one billion pounds a year over the next 10 to 15 years, decreasing thereafter.

Under government proposals the LMA will take over the liabilities and associated assets of BNFL and UKAEA.

In the case of BNFL, which the government is keen to part-privatise, these will be the Sellafield nuclear facility in Cumbria and the ageing Magnox power stations, all of which are slated for closure within the next 20 years or so.

BNFL says about 88 percent of its liabilities are already covered.

Analysts say shifting BNFL's liabilities to a government body will make the group more attractive to investors although there will remain uncertainties about other parts of the group's business.

Ireland is currently taking legal action at a United Nations body to make sure BNFL's 472 million pound Sellafield MOX Plant (SMP) does not open because of worries about low-level radioactive emissions into the Irish Sea.

Britain's Appeal Court is also set to rule in the next few days about whether the government was right in October to grant approval for the SMP to start up.

BNFL's Westinghouse division which designs and builds nuclear power stations and its AGR nuclear fuel manufacturing unit in Lancashire are seen by analysts as being among the group's strongest assets.

Hewitt said a partial sell-off of BNFL would not occur before 2004/2005.

Previous plans by the government to sell 49 percent of BNFL had to be shelved in 2000 after revelations the company had falisified data on a batch of MOX nuclear fuel sent overseas.

The international furore about the incident led to a swathe of contracts being cancelled by key customers in Japan and Germany.