Digital I&C Systems and Related Licensing Issues for the OPAL Reactor

This paper will present the "OPAL Reactor Digital Instrumentation System" focusing primarily on the digital First Reactor Protection System but also outlining the analogue Second Reactor Protection System and the Post Accident Monitoring System. This paper will describe the functions, architecture and the logic implementation of these systems. The paper will also outline the applied Standards and design documents, Human Factors, as well as the regulatory and design considerations that were applied during the design and implementation phases. A brief overview will also be given on the related Safety Category 2 Systems; the Reactor Control and Monitoring System and the Facilities Control and Monitoring System and their relationship and interfaces with the Reactor Protection Systems. Finally, the Verification and Validation processes employed in the Project will be described. (author)