Around £100 million a year could be pumped into the South West economy during the construction of a controversial new nuclear power station in the region.

Once the plant at Hinkley Point on the Somerset coast is complete, the region could reap £40 million annually and sustain 900 jobs throughout its 60-year lifespan, an independent report estimates.

The twin reactors form one of the biggest civil engineering projects ever undertaken in the South West, with economic benefits across the region.

As anti-nuclear campaigners accused French power giant EDF Energy of attempting to buy off opposition, business leaders hailed the opportunities brought about by a massive boost to pay packets during tough economic times.

Rupert Cox, chief executive of the Somerset Chamber of Commerce, said: "This project is going to provide a fantastic economic boost to South West businesses and to the community as a whole.

"It will generate unprecedented opportunities for all kinds of businesses in Somerset which we need to grasp with both hands."

Replacing Hinkley Point B, to be decommissioned in 2016 after 40 years in service, the plant will employ up to 5,000 people on site near Bridgwater during construction, bringing the region £100m a year.

In November, then Energy Secretary Ed Miliband announced Hinkley Point was one of 10 sites earmarked for a huge expansion of nuclear power.

EDF has said it wants to start its five-year build programme at Hinkley in 2012, with the power station becoming operational in 2017.

The report by the Oxford Institute for Sustainable Development says that the extra money filtering around the South West economy would come mainly from salaries spent in the area by workers and from local contractors needed to bring the reactor to life. The report states: "The development is likely to contribute to longer-term economic stability in the area.

"Overall this should lead to economic diversification away from declining sectors, offering high-quality employment and opportunities for local businesses."

It points out business opportunities will not just be limited to those involved in engineering.

Humphrey Cadoux-Hudson, EDF's managing director of nuclear new build, said: "There are major opportunities not just for local companies such as builders, plumbers and electricians, but also for support services such as caterers, hoteliers, car hire firms and trainers."

EDF added it would be investing in a construction skills centre in Sedgemoor and an apprenticeship skills hub in West Somerset to help boost the supply of workers.

Tomorrow, EDF is holding an open day in Bridgwater so suppliers can find out about contracts likely to emerge.

Ian Liddell-Grainger, Conservative MP for Bridgwater, welcomed the report.

He said: "We must maximise the business, education and training opportunities it represents for West Somerset and Sedgemoor in these difficult economic times. The new jobs and increased business activity will flow through into economic benefits for the entire community."

But Jim Duffy, of the Stop Hinkley campaign, said it was important not to let economic reward cloud judgements on the negative health and environmental impacts of nuclear.

He said: "There may be some economic benefits, certainly in terms of jobs. But most of those will be short-term in the building process. There are the long-term health effects and there is the question of what we do with nuclear waste.

"Nobody has clinched the answer to nuclear power, and there are many more imponderables. EDF should be investing in renewables rather than nuclear."