EDF : Heysham 1 nuclear power station boiler findings

Heysham 1 nuclear power station boiler findings

One of the two reactors at Heysham 1 nuclear power station operated by EDF Energy has been shut down since 11 June for refuelling and to allow investigations to take place on one of its eight boiler units. This followed tests which took place during a period of planned maintenance and inspection in 2013.

Engineers using specialist monitoring equipment have now confirmed a defect on a part of the boiler known as the boiler spine.

Although routine inspections of other boiler spines have not previously indicated any similar defects EDF Energy has taken the conservative decision to shut down Heysham 1 Reactor 2 and Hartlepool Reactors 1 and 2 that are of similar design over next few days to carry out further inspections in order to satisfy itself and the Regulator that the reactors can be safely returned to service. Until the results of the further inspections are known it is not possible to advise exact return to service dates for these four reactors, however, an initial estimate is that these investigations will take around eight weeks. EDF Energy's other nuclear power stations are not affected by this issue as they are of a different design.

Heysham 1 Reactor 1 had been operating on reduced load since its return to service from planned maintenance and inspection period in early 2014 and when it returns to service again it is likely to continue to operate on reduced load until a suitable repair strategy can be implemented.

As a result of these further inspections at Heysham 1 and Hartlepool with an initial estimate of around eight weeks the revised likely maximum theoretical output before unplanned losses for the EDF Energy Nuclear Generation Fleet in respect of the period from the 1 January 2014 to 31 December 2014 inclusive will now be c61TWh.

Explanatory Note:
Each reactor at Heysham 1 and Hartlepool has eight boiler units. These boiler units are arranged around their associated reactor in four quadrants with each quadrant containing two boiler units. Within each boiler unit are boiler 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.
Heysham 1 and Hartlepool power stations are of a unique design in the EDF Energy nuclear fleet and the continued safe operation on our nuclear power stations is not impacted.

EDF group, one of the leaders in the European energy market, is an integrated energy company active in all areas of the business: generation, transmission, distribution, energy supply and trading. The Group is the leading electricity producer in Europe. In France, it has mainly nuclear and hydropower generation facilities where 95.9% of the electricity output is CO2-free. EDF's transmission and distribution subsidiaries in France operate 1,285,000 km of low and medium voltage overhead and underground electricity lines and around 100,000 km of high and very high voltage networks. The Group is involved in supplying energy and services to approximately 28.5 million customers in France. The Group generated consolidated sales of €75.6 billion in 2013, of which 46.8% outside of France. EDF is listed on the Paris Stock Exchange and is a member of the CAC 40 index.