Retrofit Experience of Computers in CANDU Plants

Abstract

Central plant control computers have been incorporated in CANDU power plants since the early 1970's. Over the last fifteen years the processes controlled by these systems have expanded to include virtually all the major control functions in the power plants. Even though CANDU plants have used these digital systems extensively there have been some instances where it has become necessary or advantageous to replace obsolete equipment or install additional computer equipment to the reactors. This paper describes some significant examples of where this has occurred. The most extensive new application of computers in recent years has been in the area of the CANDU special safety systems. The next sections of this paper describe these systems and how programmable devices have been retrofitted into such systems.