[en] The design of the proposed Sizewell B power station and the policies which have guided design choices are outlined. The specification for Sizewell B and the production of its reference design are discussed. The Nuclear Steam Supply System and the associated safeguards systems are dealt with in more detail. The protection against hazards causing damage to plant and the protection provided to reduce radiation exposure are described. Control, instrumentation and operation of the plant are discussed. A section on quality of design follows. Finally economic aspects of the design are dealt with. (U.K.)