REGULATIONS have caused 7,000 design changes at Hinkley Point C, with a knock-on effect for cost and timescale at Britain’s first nuclear power station since 1995. 

Last week, the Office for Nuclear Regulation (ONR) released an analysis of the cause of 7,000 design changes. It stated that it was “unable to identify the detail of the 7,000 changes” identified by EDF. The industry body estimates that 5,000 design changes occurred in the period 2014-2018, and a further 2,000 were identified in 2019.

Many of the design changes were attributed to learning from other European Pressurised Reactors, and site-specific factors at Hinkley Point C. In addition, a number of design changes were driven by factors external to the ONR’s control, including directives from the Environment Agency and Health and Safety Executive.

As a result of the regulations, Hinkley Point C has had to use 35% more steel and 25% more concrete. The nuclear power station is three years behind schedule and is not expected to be operational until 2030. In addition, the overall cost in 2015 prices has soared from £26 billion to between £31 to £34 billion.

Once completed, Hinkley Point C is expected to generate enough electricity to power six million homes.

Speaking about the review into design changes at Hinkley Point C, Mark Foy of the Office for Nuclear Regulation, said: “As the UK nuclear regulator, the protection of society is our priority and is always the fundamental consideration underpinning our decisions.

“We carried out this review in the context of a wider debate around the role of regulation in the delivery of the nation’s nuclear ambitions. We have a strong relationship with NNB GenCo (EDF) who are delivering the project and worked collaboratively with them on the review to understand their source data and develop our findings.”

He added: “Based on this work, we are confident the design changes we influenced in 2012 were necessary, and our approach was proportionate and consistent with established international good practice in order to protect workers and the public.

“Our inspectors have an established presence on the HPC site and will continue to maintain targeted and proportionate oversight as the project transitions from civil construction to mechanical equipment installation. We will continue to enable the UK’s energy ambitions, while ensuring the fundamental standards of nuclear safety and security are met.”

The ONR is also overseeing the neighbouring nuclear power station, Hinkley Point B, which is approaching the 50% defueling mark. The station began its defueling stage in August 2022 following 46 years of electricity generation. The defueling process involves removing the remaining nuclear fuel from the reactors and transporting it to Sellafield for storage.

Once that work is complete, EDF will hand the station to the Nuclear Decommissioning Authority for the next step of its life, decommissioning. The station employs around 500 staff and 250 contractors and contributes around £40m a year to the Somerset economy.

Since 1976, Hinkley Point B has generated 311 Terrawatt hours (TWh) of electricity, which is enough to meet the needs of every home in the UK for almost 3 years.