Professional Engineering

With the recent affirmation of the coalition government’s affinity for nuclear power, the UK could see its first new reactor since Sizewell B built this decade. 

The new reactors will be of foreign design and, to a certain extent, built with components from overseas. One of the largest concerns has been that regulatory requirements in this safety-critical industry should not impede the building of new nuclear power stations, which the government and many energy experts say will be urgently needed when the bulk of the current generation is switched off this decade.

Three years ago, in an attempt to assess the new designs as quickly as possible, the Nuclear Installations Inspectorate (NII) started the generic design assessment (GDA). The GDA will result in the issuing of a design acceptance confirmation (DAC). Once the DAC is issued, a nuclear site licence can be issued and construction can begin. The GDA now has less than one year left to run.

Kevin Allars, director of new nuclear build, GDA, admits that industry perception in the early days of the design assessment was that it could hold back newbuild, because the NII was struggling to recruit sufficiently qualified staff. “There wasn’t sufficient resources to do the GDA at the start, but there is now,” he says. “You shouldn’t start a project until you have the resources to do it.” 

Despite an ostensibly slow start, there is little doubt that things are progressing now. The GDA has become more detailed and more resource intensive as it progresses. Of the 400 people working for the NII, 63 now work on the GDA. Some of the assessment work has been contracted out to consultants, to ensure that the project does not run late. Design documentation and progress reports are free to view on the GDA’s website, and Allars says the GDA is on target to meet to its June 2011 deadline for completion.

Although the assessment is not a legal process, it is integral to the cause of building new nuclear stations. Its purpose is ostensibly to identify parts of the design of the reactors that might not meet UK regulatory standards, by scrutinising the “generic”, as opposed to site-specific, reactor designs early on. The plan is that this will eliminate the chance that late changes to plant will be made because of last-minute regulatory problems. 

The GDA has been a four-stage process. When it was launched, four reactor designs were submitted. But, after the first two phases of preliminary assessment finished in 2008, both Atomic Energy of Canada and GE Hitachi pulled out. 

During “step three,” which concluded last year, engineers began to look in detail at the two remaining designs – Areva EPR and Westinghouse AP1000 – to identify potential regulatory problems. During the current “step four,” the problems are being examined in more detail and resolved with the reactor designers. The GDA team is now prioritising parts of the plant that have long lead times to allow operators to order those parts first. 

“EDF need to start ordering pressure vessels, control and instrumentation and parts of the pipework. They need to know that the things they are ordering will comply,” says Allars. “Then, later this year we will sit down with the operators and discuss our known unknowns, so they can make a decision about the reactors alongside other commercial factors.”

EDF is most likely to be the first to build a new nuclear power station in the UK, first at Hinkley Point in Somerset and then at Sizewell. The French energy company is expected to submit a licence application for Hinkley Point soon. The second operator expected to build this decade is Horizon Nuclear Power, a consortium of E.On UK and RWE Npower. Horizon is expected to submit applications within the next couple of years. There are also several other potential operators, such as the Iberdrola, Scottish and Southern Energy and GDF Suez consortium, which is interested in building during the 2020s.