A methodology for reliability allocation in nuclear power plants, which determines reliability characteristics of reactor systems, subsystems, and components (low-level criteria) that are consistent with a set of top-level performance criteria such as the likelihood of core damage, adverse health effects, and associated economics is presented. The methodology, based on the multiobjective programming technique in a decision-theoretic approach, does not require elaborate value judgments in determining the low-level criteria. Central to the methodology are the concept of noninferiority and finding the noninferior solution set. Several results of the methodology application to a realistic problem are also provided.