Review of Byzantine General Problems in the Reactor Protection System of Korean Nuclear Power Plants

This kind of complex error scenario is known as a Byzantine General Problem and the error is called a Byzantine Error (BE). The BE is now considered as one of the plausible common-cause failure in the nuclear power plant's (NPP) computer systems. The Reactor Protection System (RPS) in the Korean NPP consists of multiple redundant digital computer systems to increase system availability and redundancy. This system architecture is inherited form the well proved analog system's architecture. Failure modes and effects on the RPS system functions are reviewed when a BE assumed in the system's decision making logic path. For this review, one channel and two channels of BE problems in the RPS trip function are considered. If a BE occurs in any one channel of the RPS, the systems trip function has no harm affects from the BE. If two BEs occur in any channels of the RPS, the systems trip function may or may not work properly. This BE review method can be applied to other decision-making parts of the protection system in NPP