Digitial Computers in CANDU Safety Systems: Part II Implementation and Experience

Microcomputer based systems have recently been applied to CANDU safety systems. This paper describes three specific systems, a monitoring system, the programmable digital comparator (PDC) system, and a fully computerized shutdown system prototype. The system configurations, the hardware and the software used to implement these designs are discussed. Each of these systems uses commercial off-the-shelf hardware which has been modified and qualified when necessary to meet specific power plant requirements. The preliminary experience which has been gained with the systems already in operation also summarized.