Investigations into potential cracks in boiler spines at two units at each of the Heysham I and Hartlepool sites are likely to take until the end of the year to complete, EDF Energy has announced.
On 11 August, the company said it had shut down Heysham I unit 1, in northwest England, in June after discovering a fault in a boiler spine and taken the “conservative decision” to halt the second reactor there, and two at its Hartlepool site in the northeast of England, “which are of a similar design.” At that time, EDF Energy said it expected the units to remain closed for about two months while investigations are carried out.
However, the company has now announced that “a detailed and fully resourced boiler inspection program” has begun at the four advanced gas-cooled reactors (AGRs) which will take longer than original envisaged. EDF Energy said this has involved “working with key suppliers to identify and put the necessary equipment and people in place to undertake this complex and specialized engineering program.”
Each reactor at Heysham I and Hartlepool has eight boiler units. These boilers are arranged around their associated reactor in four quadrants with each quadrant containing two boilers. Within each boiler are tubes assembled in a coil formation around a central forged metal tube called a boiler spine. The boiler spines support the weight of the tubes around them.