On 7 February Scotland's Torness 1 advanced gas-cooled reactor (AGR) was brought offline for a planned maintenance outage to perform maintenance work costing £30 million in total. The scope of work includes replacing three generator transformer phases, each weighing 250 tonnes, turbine rotor and generator rotor exchanges.
Another job is the first-of-a-kind replacement of the electrical drives for the reactor gas circulators.
In addition, many key components are being inspected, including reactor internals, fuel channels, boilers, steam pipes, and electrical and control systems.
More than 13,000 separate work items are scheduled. Site staff numbers will double; 500 specialist workers are being brought in to help out.
In August 2013 Torness station (consisting of two units, 583 and 592 net MWe nominal full load), generated 200 TWh since start of operation in 1988. Like Hinkley B, Hunterston and Heysham B, both Torness units are refuelled online, at low power, unlike Dungeness B, Hartlepool and Heysham A reactors, which must be shut down to refuel.
Picture: Staff manoeuvre a 30-tonne low-pressure steam crossover pipe from the Torness 1 turbine.