Sizewell is a nuclear power station in Suffolk, near Leiston. It is operated by British Energy, which is owned by EDF (80%) and Centrica (20%).

At present, there are two reactors at Sizewell.

• Sizewell A: shut down since 31 December 2006, Sizewell A is an old-style Magnox reactor.
• Sizewell B: operational since 1995, Sizewell B is presently Britains only PWR reactor.

There are plans to build two EPR reactors as Sizewell C.