EDF Energy took the decision to bring Sizewell B offline in March following the failure of some heaters in a component known as the pressuriser.

Using bespoke designed equipment, video footage was taken of the pressuriser which enabled engineers to examine it in the smallest detail. A repair strategy was then tested on a 16metre x 2 ½ metre replica of the equipment before being successfully completed on the pressuriser.

EDF Energy’s parent company EDF has worked on a five-year programme to re-design the heaters within the reactors in France and their expertise in this area has helped determine the new model of heater which will be used at Sizewell B.

Jim Crawford, Sizewell B Station Director said: “Working within the EDF family of companies we have been able to draw on international expertise throughout this project. This has given us access to industry experts who, working closely with our local team, have been instrumental in bringing Sizewell B back to service.”

A project team, which included EDF personnel from France, was established to oversee the station’s return to service. EDF Continuous Improvement Director Alain Peckre was based on the project board and has experience working within EDF Energy’s UK nuclear business.

Alain Peckre said: “ Working together, colleagues from France and the UK were able to share our experience gained on the re-design of the heaters used in the French reactors which has helped determine the new model of heater which will be used at Sizewell B.”

The work carried out on repairs has been regularly monitored by the industry regulator the Nuclear Installations Inspectorate, part of the Health and Safety Executive.

The HSE Nuclear Directorate gave its consent for the power station to restart. They undertook a significant programme of inspections and assessments and a summary of their work is provided on the HSE website which concludes "HSE Nuclear Directorate has sufficient confidence that the modifications to the pressuriser have been adequately conceived and executed and that the Sizewell B reactor is safe to operate".

Sizewell B is committed to being a good neighbour and has regularly communicated with the local community throughout this outage. In addition to the routine letters, newsletters, and attendance at the Site Stakeholder Group meetings, the station has also introduced a telephone information service for local residents to call for updates about events at the station.

Sizewell B power station is the most recent nuclear power station to be built in the UK and celebrated 15 years of low carbon generation in February this year. The station employs over 500 staff based on the Suffolk coast and contributes some £30million into the local economy every year.