Realistic Analysis of Nuclear Power Plant Operating Limit Setting

Nuclear power plant (NPP) operating limits are vital for safety, traditionally derived from conservative Deterministic Safety Analysis (DSA) which often sacrifices operational flexibility due to simplified uncertainty treatment. This study explores the application of Best-Estimate Plus Uncertainty (BEPU) methods to optimize operating limits setting, providing a more realistic and precise assessment of safety margins. BEPU quantifies uncertainties by treating input parameters as random variables, evaluating the probability distribution of safety-related outputs against defined safety criteria. This typically requires compliance with statistical tolerance limits at a specified confidence level. Such a methodology can refine core operating limits, optimize reactor protection and instrumentation setpoints, and release operational margins beyond traditional DSA. While BEPU promises enhanced flexibility and efficiency, challenges in data quality, computational cost, and regulatory acceptance persist. This paper specifically analyzes the practical application of BEPU in optimizing NPP operating limits, proposing a detailed methodology that addresses the critical consideration of required computational iterations to satisfy statistical tolerance limits, thus offering actionable insights for implementation and enhancing nuclear safety and operational economy.