Data Communication in a Nuclear Digital I and C System--The Korean Experience
Tae-Wook Lim, Jae-Youb Byun, James S. Jhun · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 2001
Full-scale use of a microprocessor-based digital instrumentation and control (I and C) system for the control of nuclear power plants (NPPs) in Korea has spanned more than 14 years and covered eight plants. Here, the discussion centers on the design experience of the data communication portion of the digital I and C systems along with the associated nuclear licensing issues. The first two plants included only the on/off (binary) controls in the digital I and C system. Later plants had a fully expanded scope of plant controls including continuous (analog) controls. One of the digital systems used bus network architecture, while the other is based on a ring network configuration. The design differences, advantages, disadvantages, and specific licensing issues of these two configurations unique to the NPP operating environment are discussed. From the Korean experience it is clear that digital data communication enhances operability by providing system performance status and diagnostic surveillance data on a real-time basis. The ring network configuration showed superior system response time characteristics over the bus network, but it has a weakness in maintaining network independence and preventing propagation of a network fault condition.