4 Sep 14

EDF Energy update on Heysham 1 and Hartlepool Power Stations

On August 11, EDF Energy reported that the four nuclear reactors at its Heysham 1 and Hartlepool power stations would be shut down to allow a detailed programme of boiler inspections to take place.




This precautionary measure was taken after the discovery of a crack on a component known as a boiler spine at Heysham 1. Hartlepool power station was also shut down because both stations share the same unique design with each of its 16 boilers supported by this boiler spine component.

Other advanced gas-cooled reactors in the UK have a different and more conventional boiler design without a boiler spine and they are manufactured from different materials. Therefore there is no risk that they could suffer from the same issue.

Since then, EDF Energy has put in place a detailed and fully resourced boiler inspection programme at both sites and further boiler inspections are now underway. This has involved working with key suppliers to identify and put the necessary equipment and people in place to undertake this complex and specialised engineering programme.

Engineers have recently been able to begin their inspections and the first two inspections have been completed. The engineers found no defects on these spines.

EDF Energy has identified that to bring these reactors back into service, the programme must:





  • Complete the inspections to verify there are no further defects which could develop into cracks
  • Understand in detail the cause of the crack found on the boiler spine at Heysham 1
  • Develop detailed designs and techniques for modifications to mitigate the impact of any defects
  • Then implement modifications if necessary
During the coming weeks the programme team will focus on completing the inspections and work to build a robust case for the safe continuing operation of the boilers. This “safety case” is subject to approval from the independent nuclear regulator, the ONR (Office for Nuclear Regulation).

Now that the programme has been developed in detail and is underway, EDF Energy can give information on the estimated dates for returning the four reactors to service. Depending on the progress of the programme and any necessary modifications, the company expects there to be a phased return to service between the end of October and the end of December, 2014.

Dates for returning the stations to service depend on the findings and completion of the inspections. EDF Energy will give further updates on the progress of the programme when it is able.

EDF Group has already identified actions to mitigate the financial impact of the lower nuclear output.



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Boiler Spine, each reactor at Heysham 1 and Hartlepool has eight boilers, which remove heat from the reactor core and generate steam. This is used to produce electricity in the power stations’ turbines. Each boiler comprises a complex array of boiler tubes with a central cylindrical boiler ‘spine’ that provides structural support to the tubes. Other advanced gas reactors have a more conventional design with boiler tubes supported at multiple points rather than having a boiler spine.

You can download images, diagrams and videos at our online newsroom


Heysham 1 and Hartlepool power stations both began generating electricity in 1983 and each has two advanced gas-cooled nuclear reactors. Heysham 1 supplies 1155MW to the Grid and Hartlepool supplies 1180MW.




EDF Energy

EDF Energy is one of the UK’s largest energy companies and the largest producer of low-carbon electricity, producing around one-fifth of the nation's electricity from its nuclear power stations, wind farms, coal and gas power stations and combined heat and power plants. The company supplies gas and electricity to 6 million business and residential customer accounts and is the biggest supplier of electricity by volume in Great Britain.

EDF Energy’s safe and secure operation of its eight existing nuclear power stations at sites across the country makes it the UK’s largest generator of low carbon electricity. EDF Energy is also leading the UK's nuclear renaissance and has published plans to build four new nuclear plants, subject to the right investment framework.

These new plants could generate enough low carbon electricity for about 40% of Britain’s homes. They would make an important contribution to the UK’s future needs for clean, secure and affordable energy. The project is already creating business and job opportunities for British companies and workers.

Through Our Better Energy Ambitions, EDF Energy has developed one of the biggest environmental and social programmes of any British energy company.

In 2014 EDF Energy received seven ‘Big Ticks’ in the Business in the Community (BITC) Responsible Business Awards. In 2013 EDF Energy received the Environmental Leadership for Behavioural Change Award in the national Environment and Energy Awards and was highly commended in the first ever pan European Corporate Social Responsibility Awards scheme for its Sustainable Schools programme – the Pod.

EDF Energy is part of EDF Group, one of Europe’s largest power companies. The company employs around 15,000 people at locations across the UK.

To find out more about the UK's energy challenges look at www.edfenergy.com/energyfuture/