The French owners of Scotland’s two

remaining nuclear power generators are spending £30 million in a round of scheduled maintenance on Hunterston B in Ayrshire in a major one-off investment.

The latest "MOT" for the 965MW generator near West Kilbride on the Ayrshire coast involves 12,000 separate pieces of work, headed by the replacement of a giant generator transformer, and the replacement of two gas circulators and two low-pressure turbine rotors.

Each of Hunterston’s two generating units must be overhauled once every three years according to rules laid down by UK regulator, the Office for Nuclear Regulation. In 2012, the plant – originally intended to close in 2011 then extended to 2016 – was given the green light to continue its working life until 2023. Further short-life extensions have not been ruled out, but are not currently under consideration according to EDF.

The station supplies 15 per cent of Scotland’s supply of baseload power, while EDF’s other nuclear power station, Torness in East Lothian, supplies 19 per cent, meaning that Scotland now relies on the two ageing facilities for 34 per cent of its steady

supply.

Colin Weir, Hunterston’s station director, said: “Once again Hunterston B will turn to a number of local firms, with whom we have a tried and trusted relationship, to provide essential services during this outage. We are impressed by the high standards of the companies we work with and the quality of their workmanship. These companies will work alongside specialist firms from across the world, who are

leaders in their field.”

Compared by EDF to a car having an MOT and service but on a much bigger scale, the planned outage is the culmination of two years of planning by station staff. A new generator transformer – the part of the plant which transfers the produced electricity produced to the national grid – has been brought by sea from Germany, requiring the removal of the outer wall of part of the plant, separate from the nuclear reactor. The station’s team will also replace two gas circulators which circulate the cooling carbon dioxide gas around the reacto, while the high pressure turbine rotor and two low pressure turbine rotors that are in constant contact with the super-heated steam.

The number of workers on site will nearly double with around 500 specialist workers brought in to assist Hunterston B staff.

Local suppliers in Ayrshire are set to take a share of contracts worth tens of thousands of pounds to the local economy. Many hotels, caravan parks and B&Bs will all benefit from putting up contractors while they are based at the station.

Hunterston B nuclear power station provides enough power for around 1.5 million homes per year in the UK (58 per cent of Scottish homes). EDF claims this has avoided 5.2 million tonnes of CO2 per year, and in the total 39 years of operation, 169 million tonnes of CO2, equivalent to taking 2.3 million (eight per cent) of the UK’s passenger cars off the road.

Hunterston also contains a visitor centre, awarded five stars by national tourism agency VisitScotland, which contains an interactive exhibition, a classroom and offers tours of the power station. The exhibition explains how electricity is generated in a nuclear power station. It also covers safety on site, radiation, nuclear waste and other forms of electricity generation.

While the Scottish Government is firmly opposed to the construction of a new generation of nuclear power stations, ministers have declared themselves “perfectly open” to the continued operation of Hunterston and Torness.

A spokesman said: “We have consistently made it clear that nuclear energy will be phased out in Scotland over time, with no new nuclear build taking place in Scotland. But we have also consistently made clear that this does not preclude extending the operating life of Scotland’s existing nuclear stations."

to help maintain security of supply over the next decade while the transition to renewables and cleaner thermal generation takes place.”

The environmental body WWF Scotland, which objected to Hunterston’s life extension, has branded nuclear power the “ultimate unsustainable form of energy”.