The UK government in late October shelved plans to build the Severn barrage—a project that would have involved building a 10-mile dam across the mouth of the Severn River—after a two-year-long feasibility study failed to convince ministers to use public funds to build it. The Department of Energy and Climate Change instead gave its long-awaited approval to eight sites for new nuclear reactors, saying that private companies could begin building the country’s new fleet of reactors, provided no public subsidy is involved.

The Severn estuary, which opens to the Bristol Channel between southern Wales and Devonshire in southwestern England, has tidal variations of as much as 29 feet most of the year and almost 47 feet in springtime; only the Bay of Fundy in Canada has higher maximum tides. A number of studies had suggested that projects damming the estuary could produce as much as 5% of the country’s electricity.

The government’s feasibility study examined several large-scale concepts for damming the Severn estuary as part of the so-called Severn barrage project, including proposals for three barrages and two lagoon-type energy projects. The most high profile of these was the 10-mile Cardiff-Weston barrage, costs for which had been initially estimated at £15 billion, but which doubled to more than £30 billion (Figure 6). Though the government said it recognized “the significant UK resource that the Severn estuary presents” and did not rule out building a barrage in the future, it said it did not see a “strategic case” to build the project until at least 2015.

6. No dam way. The UK government in October dropped plans to build a 10-mile tidal barrage across the Severn Estuary after an official study said there was no “strategic case” to invest public funds in the £30 billion project. The project could have supplied up to 5% of the UK’s power, the government said. A similar project, La Rance Tidal Power Station (shown here), exists on the Rance River estuary, in Brittany, France. Built in 1966 and currently owned by Électricité de France, the Rance barrage produces 600 GWh annually via 24 turbines. Source: Wikimedia Commons

The eight approved nuclear sites all have existing reactors in the vicinity. They are: Bradwell, Essex; Hartlepool, Durham (Figure 7); Heysham, Lancashire; Hinkley Point, Somerset; Oldbury, South Gloucestershire; Sellafield, Cumbria; Sizewell, Suffolk; and Wylfa, Anglesey. The first new nuclear plant, built by Électricité de France (EDF) at Hinckley Point, could come online as soon as 2018. As with three other reactors EDF has planned to build in the UK, the reactors will likely be EPRs. The Horizon joint venture between German giants RWE and E.ON, which also plans to build 6 GW of new nuclear by 2025, has not announced its reactor design of choice. The companies must choose between AREVA’s EPR and Westinghouse’s AP1000, third-generation reactor designs that are expected to be approved by the UK’s Health and Safety Executive by June 2011.

7. Ramping up reactors. The UK government in October approved eight sites for new reactors, allowing the country to move forward with plans to build a new fleet of nuclear plants. The sites are in the vicinity of existing nuclear plants, such as the Hartlepool Station, shown here. The government said new nuclear capacity would have to built without public funding. Courtesy: British Energy

The UK currently has 19 reactors generating about 18% of its electricity, and all but one reactor will be retired by 2023. As Energy Secretary Chris Huhne noted, at least a quarter of the UK’s electricity generating capacity needs to be replaced by 2020. The government’s recently revised national policy statements on the country’s energy plans show that half of the new capacity built by 2025 is expected to come from renewables—mostly from wind. “I’m fed up with the stand-off between advocates of renewables and of nuclear which means we have neither,” he said. “We urgently need investment in new and diverse energy sources to power the UK.”

—Sonal Patel is POWER’s senior writer.