[en] Automatic control using centralised or distributed computer systems has been used on all the UK Central Electricity Generating Board's nuclear plant but the capability of the control systems has been continually increased because of increase in plant ratings and the consequent faster plant responses and reduced plant margins. New systems must also cover a wide range of load. Digital systems are used and the system used at Hartlepool and Heysham 1 is outlined showing the controlled parameter, measured parameter and the number of control loops needed. Computer hardware costs are decreasing and the programming is a more significant part of the cost. The use of very high level languages such as CUTLASS simplifies programs. The control and computer systems used by the CEGB are described. Normal operation can satisfactorily be dealt with but fault conditions are more difficult. Current alarm schemes are discussed. Even with sophisticated computer techniques operators are still necessary as the focal point of reactor operation. (U.K.)