One of the nuclear reactors at Heysham 1 power station in Lancashire has been taken out of service for a major maintenance programme.
Around 1,000 extra workers will join the site’s 700-strong team during the eight-week ‘outage’ period.
The team will carry out more than 12,000 separate pieces of work – each planned during two years of preparation.
Richard Bradfield, station director at Heysham 1, said: “We spend many months planning for this intense period of work for the station. But we, and our contractors and other specialists, are ready.
“Locally the area benefits from the influx of many hundreds of contractors who stay locally for the duration of the shutdown.”
The extensive programme of work will see inspections inside the reactor, as well as the installation of new equipment at the plant.
The biggest projects include turbine and generator inspections and maintenance as well as replacing one large gas circulator that helps with cooling the reactor.
The maintenance periods, known as ‘statutory outages’, take place every three years on each reactor and are planned in advance with the National Grid to ensure that there is no impact on the national electricity supply.
Heysham 1’s other reactor is due to continue operating normally throughout the period.
In 2016 the power station saw its operating life extended until 2024.
Heysham 1’s two reactors generate enough low carbon electricity to power around two million homes, so saving around six million tonnes of carbon dioxide emissions each year.
The outage began on Monday.