Investing in Sizewell B’s long-term future

A multi-million pound overhaul of the Sizewell B nuclear power station is underway – and the work will bring a big boost to the Suffolk economy.

Every 18 months teams at Sizewell B Power Station take the site’s nuclear reactor offline for refuelling and other works designed to improve the efficiency of the plant’s operations.

The reactor, which every year generates enough zero-carbon electricity to meet the needs of more than 2.5m homes, was taken offline on 11 October for the work which will take around two months and cost approximately £75m.

Robert Gunn, Station Director at Sizewell B said: “These outage periods are tremendously important for us. They allow us to examine our plant in a way we can’t do when we are generating and they give us the chance to complete major improvement projects. 

“Beyond this they are important for the Suffolk economy. When we undertake an outage we need help from hundreds of external contractors who then live, shop and eat locally while the work is ongoing. 

“During this outage we will bring in more than 1000 extra staff to deliver more than 12,000 tasks. 

“This brings in millions of pounds of extra income to our area’s hotels, restaurants and shops. And it doesn’t stop there, we also use local companies to complete work for us. This time, for example, Bungay based precision machining solutions firm Webb Engineering will be helping us complete these works.” 

Sizewell B started generating electricity in 1995 and has generated over 258 terrawatt hours of electricity (TWh) – that's enough to meet the electric needs of every home in Suffolk for more than 190 years.

EDF acquired all eight power stations in the UK nuclear fleet in 2009 and, since then, has invested around £1.2bn in Sizewell B to maintain reliability and ongoing zero-carbon electricity generation.

During the outage teams at Sizewell B will;

• Replace giant rotors (one high pressure rotor, measuring 6.6m x 1.8m and which weighs about 30 tonnes and three low pressure rotors 7.3m by 3.6m, which weighs about 58 tonnes) in one of the station’s turbine generators. The rotors spin so fast that we estimate they have spun more than 1bn times in the past year. 
• Replace about a third of the fuel assemblies in the reactor
• Carry out detailed inspections of reactor systems
• And examine high pressure pipework across the reactor system

Robert added: “Sizewell B has been quietly powering the nation with zero-carbon electricity for 29 years and as proud as we are of that history, we are constantly looking to the future.

“We know the nation needs us for the longer term. Britain’s drive towards clean power and more secure energy needs nuclear to complement renewables, both new projects like Sizewell C as well as existing stations such as Sizewell B. 

“We have carefully managed and operated this plant and our reactor for nearly three decades and our future plans are to extend our lifetime out to 2055. As the station is currently due to generate until 2035, there is no immediate need to make a final investment decision. As well as finalising the technical case, we are seeking greater cost certainty and confidence in the long-term commercial case to enable a final investment decision when ready.”

Notes to Editors 

• Since 1995, the power station has generated 258 terrawatt hours (TWh) of zero-carbon electricity: enough to power every home in Suffolk for more than 190 years, preventing 87m tonnes of CO2 emissions from entering the atmosphere.
• The site employs over 600 full time EDF staff and around 250 full time contract partners.
• Sizewell B has outages about every 18 months. The main function of an outage is to replace spent fuel. There are 193 fuel assemblies in the reactor each containing roughly 97,000 pellets. Each tiny pellet has the same energy as 800kg of coal. And each refuelling outage we replace one third of the fuel, this means that each fuel assembly lasts approximately 4.5-5 years in the reactor. 
• During this outage, one of the most significant projects will be the turbine rotor replacement which will cost £12m. 
• Other works being undertaken during this outage include inspections of pipework in and around the reactor as well as a ten yearly regularly scheduled inspection of the interior of the nuclear reactor. 
• After triggering its Development Consent Order at the start of the year and securing a Nuclear Site Licence in May, Sizewell C is moving at pace. The government announced a further £5.5bn of funding for the project in May.   
• A once in a generation opportunity for East Suffolk, Sizewell C is creating thousands of new jobs, apprenticeships, and training opportunities for the region. It has allocated £250m in local funding, and once operational it is expected to contribute £40m a year to the local economy and employ 900 people in high-skilled, well-paid jobs.