ABSTRACT
Technical specifications for nuclear power plants define limits and conditions to assure that the plant is operated in a manner that is consistent with the analyses and evaluations in the plant’s Safety Analysis Report. Requirements of technical specifications are originally based on deterministic analyses and engineering judgment. However, experiences with plant operation indicate that some requirements may be inadequate from risk profile point of view. Particularly Allowable Outage Timing (AOT) could be an important factor for plant safety, whereas clear justification for AOT values is not provided. This paper describes an attempt to check adequacy of AOTs defined in the technical specification used for Armenian NPP Unit 2. Verification was done using single AOT criteria developed using plant-specific information.
