The design and management of cables and supporting steelwork systems for Sizewell `B´

Sizewell B nuclear power station has over 33000 cables connecting in excess of 20000 items of equipment. Over 120 cable types are used. Many cables supply power to, or monitor, safety category 1 equipment essential to the safe operation of the reactor and supporting systems. Cables must be designed to survive the postulated hazards of reactor systems fault, earthquake, fire and radiation exposure. As with electrical equipment, cables are designated either essential (to reactor safety operation) or nonessential. The author describes the required safety design criteria, how these are achieved and the design approaches to seismically qualified supporting steelwork. Also described are the cable design, scheduling, routing and planning processes which lead to the required installation and commissioning activities being completed in a controlled and timely manner