Difference the reactor has made

Sizewell B has made a significant contribution to the generating capacity of the UK since it started producing electricity in 1995.

The plant produces 3.1% of the UK's energy needs. This represents low carbon electricity for around 2.5m homes and businesses.

Additionally, the power station and its construction had a direct effect on the economy. Over 20,000 jobs were created to build the station – many for people working for local firms.

The plant continues to contribute to the local economy as it currently employs around 770 full-time or contract workers.

How Sizewell B was built

Safety was a key challenge for engineers working on the construction of Sizewell B.

The nuclear reactor, along with its cooling circuit and steam generators, is contained inside a 65m high, 45m diameter pre-stressed concrete building. The walls are 1.4m thick and designed to withstand 'catastrophic' events such as plant failure or an earthquake without leaking.

Engineers lined the station interior – floor, walls and dome – with gas-tight steel 6mm plate. This weighs 2,000 tons and is fastened to the concrete.

Producing concrete to build the plant was a major part of work on the project. Enough was poured during construction to fill the Royal Albert Hall 5 times over.

Engineers used 70,000 tonnes of steel bars for Sizewell B's pipework. The cabling used for instrumentation alone would run from London to Brighton.

Additional safety measures designed into the plant include an exact replica of the power station's control room. Employees are trained here before they're allowed access to the real thing.

Sizewell B won the Supreme Award at the British Construction Industry Awards in 1994.