This article presents a practical implementation of a safety verification framework for nuclear power plants (NPPs) based on fuzzy logic where hazard scenarios are identified in view of safety and control limits in different plant process values. Risk is estimated quantitatively and compared with safety limits in real time so that safety verification can be achieved. Fuzzy logic is used to define safety rules that map hazard condition with required safety protection in view of risk estimate. Case studies are analyzed from NPP to realize the proposed real-time safety verification framework. An automated system is developed to demonstrate the safety limit for different hazard scenarios.

Many energy and production facilities are operating without clear formal safety requirements, which are con- sidered the base for good process safety management practices. Safety requirements are typically specified during process design based on identified hazard scenarios. This paper proposes a practical framework and methods to systematically synthesize safety requirements based on qualitative and quantitative fault and hazard scenarios. Our aim will be to design a proper safety verification framework which would provide some guidelines regarding the sequence of steps to be taken in the plant for the verification of the safety of that plant. The objective of this paper is to show how the safety verification techniques meet the safety requirements of any production plant. We will clarify Safety Life Cycle and the detailed steps for safety design and verification and also analyze current practices and challenges of safety verification in instrumented/non-in- strumented systems. We will also develop possible activity model for safety verification process and will propose safety requirements representation that will facilitate safety verification. Case study of experimental setup is used to demonstrate the proposed framework, which will support safety design and verification