ScholarWorks@중앙대학교

초록

Following the Three Mile Island accident, risk has become a fundamental concept in evaluating nuclear power plant (NPP) safety. Probabilistic Safety Assessment (PSA) is widely used to quantify risk by integrating accident frequencies and radiological consequences. However, the comprehensive PSA process, particularly level 3 consequence assessment using codes such as MACCS, demands significant computational resources and is not well-suited for rapid evaluations during design optimization. This challenge is intensified by recent Risk-Informed and Performance-Based (RIPB) regulatory frameworks, which require comprehensive risk quantification explicitly accounting for accident consequences across diverse accident sequences. To address this limitation, this study proposes a computationally efficient methodology based on a correlation model linking source-term releases to resulting radiological consequences. This approach enables the development of intuitive risk profiles that can enhance the practical utilization of risk information. As a case study, the proposed framework was applied to core damage accident sequences identified in the OPR-1000 level 1 PSA model, focusing on two initiating events: 1) loss of feedwater (LOFW), and 2) small break loss of coolant accident (SLOCA). Frequency-Consequence (F-C) curves were developed to compare the relative risks of the two events and evaluate the effects of severe-accident mitigation measures. The results demonstrate the initial applicability of the proposed methodology and indicate its potential to support more efficient risk-informed safety evaluations and decision-making.

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