Comparison of IEC and IEEE Standards for Computer-Based Control Systems Important to Safety

The collections of IEEE and 1EC standards have some overlap, but in many cases cover significantly different topics. For example, 1EEE standards go to great depth on environmental qualification of many specific types of components, while IEC covers the topic only at the general level. Conversely, certain IEC standards deal with specific instrumentation and control functions, a topic area where IEEE standards are largely mute. This paper studies two questions related to the above observations. Which standards in each body should be coordinated with each other? What opportunities exist for the two bodies to build on each other's standards to efficiently improve upon the coverage of their sets of standards? Poor coordination between the two sets of standards poses a problem for the developers of systems for plant upgrades. Developers must try to address both sets of standards to avail themselves of a sufficiently broad market. Additionally, the IEEE and IEC standards together form a more comprehensive set of guidance than either set alone. If the interfaces between the standard sets were smoother, plant staff and system designers would have a better set of tools to help in the design and specification of I and C upgrades. To understand the similarities and differences between 1EC and IEEE nuclear power standards layer diagrams were developed for each set of standards.