Civil infrastructure facilities are exposed to extreme natural and manmade hazards. The public tend to overstate the risks from such hazards that are feared or poorly understood, where the exposure to the population is involuntary in nature, and where fatalities or permanent injury are likely and severe. Such exaggerations of perceived risk influence policy-making and the development of risk mitigation strategies. Regulatory decision-making for nuclear plant safety represents a case that is affected by such exaggerated risk perception. In this paper, we analyze rule-making by the US Nuclear Regulatory Commission (NRC)'s regarding the operation of nuclear plants utilizing cumulative prospect theory (CPT), which permits risk-averse behavior to be modeled in assessing both likelihoods and consequences of a hazardous event.The investigation is extended to different requirements that are influenced by the International Commission on Radiological Protection, leading to an international perspective on the role of risk perception in regulatory decision-making.