Abstract :
The operation of Sizewell B nuclear power station relies on auxiliary plant and services whose electrical power is supplied from the AC power systems and control and instrument equipment whose electrical power is supplied from the DC or battery backed uninterruptible power supply (UPS) systems. The author considers the designs and developments of the DC and UPS electrical power systems and illustrates how they meet the safety and licensing requirements. He particularly discusses the use of sealed lead acid batteries, the first nuclear electric power station to have a significant installation of these cells, and proposals for their maintenance and testing