THE Windscale nuclear reactor, site of Britain’s worst atomic accident, will be made safe almost 30 years earlier than planned, saving the taxpayer an estimated £4 billion.

The UK Atomic Energy Authority has told ministers that it will return Windscale in Cumbria to a safe state by 2017, some 60 years after its fire, ranked as one of the world’s three worst nuclear accidents.

The UKAEA, responsible for decommissioning some of the oldest nuclear reactors, plans to bring forward the clean-up timetable for its four main properties by about two thirds, The Times has learnt.

The move will substantially reduce the £8.9 billion cost of cleaning up the nation’s crumbling nuclear inheritance. Decommissioning the entire civil nuclear legacy is likely to cost £50 billion.

Dipesh Shah, chief executive of UKAEA, recently told the industry its aim should be to “halve the costs and halve the time” of decommissioning.

Speeding up the timetable will help the nuclear industry to make the case for building reactors. No commercial reactors have begun operating for almost a decade because of the problem of cleaning up retired reactors. Mr Shah, who joined UKAEA from BP in November, said: “UKAEA has more experience in decommissioning nuclear sites than any other organisation in Europe. This is underlined by the commitments we have made to Government to shorten the timescales for decommissioning and reduce the costs while maintaining our high standards of safety and care for the environment.”

The plan to accelerate the clean-up of some of the most infamous nuclear sites come as the Department of Trade and Industry prepares to set up the Nuclear Decommissioning Authority, which will take over managing the £50 billion of nuclear liabilities next April.

Windscale, a prototype for seven gas-cooled reactors, is the first UK commercial nuclear reactor to be dismantled and one of only a few worldwide. The famous “golf ball” dome of the reactor will be demolished next year, after the removal of the graphite reactor core.

The UKAEA had planned to leave the outer domed shell and concrete bioshield intact until 2040 to allow most of the contamination to decay. But engineers discovered that the graphite core was not damaged during the notorious 1957 fire, as previously thought, which meant that the decommissioning could proceed more quickly.

The clean-up of other nuclear sites owned by UKAEA is also being accelerated. At Winfrith, in Dorset, the work is expected to be completed in 2020, some 30 years early.

Nuclear material will be removed from the site in the next two years, a move that will mean the nuclear constabulary, which protects atomic supplies, can be replaced by commercial security guards.

The east end of the Winfrith site has become a business park with many science and technology businesses that have spun out of the UKAEA.

At Harwell, in Oxfordshire, the first site for nuclear research and development, reactors will be safe by 2015, five years earlier than planned.

The decommissioning of the experimental reactor at Dounreay, in Caithness, will be completed in 2047.

Contractors that stand to benefit from the accelerated decommissioning include British Nuclear Fuels Environmental Services, RWE Nukem, WS Atkins, Amec, Fromatome and Mitsui Babcock.

Windscale’s decommissioning has already aroused strong overseas interest and UKAEA hopes that this field will be a big growth area for it in the years to come.