Hunterston B reactor achieves electricty generation record

One of Scotland's two remaining nuclear power stations has achieved its longest uninterrupted period of electricity generation in four decades.

Hunterston B nuclear power station in North Ayrshire was commisioned in 1976. Picture: Allan Milligan/TSPL

Hunterston B has operated two reactors from a site on the North Ayrshire coast since 1976.

When one of the reactors was taken off line on September 8 for maintenance work it had been running for 495 days - the longest run in the station’s 41 year history.

The facility, operated by French energy giant EDF, is due to close in 2023. Its sister station, Hunterston A, was decommissioned in 1990.

EDF carries out a statutory outage on each of its reactors every three years. These are planned in advance with the National Grid to ensure there is no impact on the national electricity supply.

The other reactor at Hunterston B is due to continue operating normally throughout the period of works.

During the outage workers will carry out more than 10,000 separate pieces of work, each carefully planned during the last two years of preparation, including inspections of a range of systems including the boilers, electrical systems and the graphite core. The biggest projects will include replacing three low pressure turbine rotors and the main generator electrical rotor.

Hunterson B and Torness in East Lothian are the last nuclear power stations north of the border, with the Scottish Government firmly opposed to more being built.

Chapelcross, a station near Annan, was decommissioned in 2004.

Station director Colin Weir said: “This period of maintenance marks the best run of electricity generation in Hunterston B power station’s 41 year history.

“This achievement is testament to both the planning and commitment of the station’s dedicated workforce and the investment by EDF Energy. The outage will see around £20m of investment in the power station and will give us the chance to do inspections and carry out pieces of work we are not able to perform when the reactor is operating.

“As part of this maintenance we will be working with local suppliers and bringing in an additional 450 workers who will be staying in local hotels eating in the area’s restaurants and using taxi firms.”