An Operator Support System Framework and Prototype for Initial Emergency Response in Nuclear Power Plants

Abstract

Nuclear power plant operation can be categorized with three: normal, abnormal and emergency operation. Especially in emergency operation, operators are exposed to highly stressful condition, since immediate and appropriate mitigations are required. To reduce human errors in this situation, emergency operating procedures (EOPs) are used, which provide appropriate tasks to mitigate situations and support diagnosing symptoms of nuclear power plants. However, human error is still a major contributor for nuclear power plant accident. In order to reduce human error, many operating automation methodologies are researched. However, in the nuclear field that requires a high degree of safety, it is difficult to quickly apply automation technology, so it is necessary to apply and verify low-level intelligent operator support systems. In this paper, we propose concept of an intelligent operator support system replacing EOPs that have initial responses. The proposed operator support system has a parallel structure that monitoring tasks are conducted simultaneously in contrast with EOPs that are performed sequentially. From this monitored information, the system provides intuitive and accurate information to the operator through the state of critical safety functions and the master logic diagram. In addition, information on latent risks due to auxiliary system failure is also provided to the operator using multilevel flow modelling technique. This system is expected to replace initial response emergency operating procedure and to reduce responding time by the parallel structure.