China's First Industry Standard for LOCA BEPU Analysis, Led by CGN Research Institute, Officially Released

Recently, approved by the National Energy Administration, the energy industry standard "Technical Requirements for Best Estimate Plus Uncertainty Analysis of Loss of Coolant Accident in Pressurized Water Reactor Nuclear Power Plants" (NB/T 20751-2026), led by CGN Research Institute, was officially released. The standard was developed under the leadership of the Research Institute, in collaboration with the Nuclear and Radiation Safety Center of the Ministry of Ecology and Environment, China Nuclear Power Research and Design Institute, Shanghai Nuclear Engineering Research and Design Institute, Hualong Nuclear Power Technology Co., Ltd., and China Nuclear Power Engineering Co., Ltd., among other organizations. It will come into effect on December 26, 2026.

This standard is China's first technical standard for Best Estimate Plus Uncertainty (BEPU) analysis of Loss of Coolant Accident (LOCA) in pressurized water reactor nuclear power plants, filling the standardization gap in this technical field within China's nuclear power industry. Based on the actual needs of China's pressurized water reactor nuclear power plants, the standard systematically defines the development process and application guidelines for BEPU analysis methods for LOCA accidents in PWRs, providing a unified and scientific standard basis for the industry.

The release of this new standard marks the upgrade of China's nuclear safety analysis system from traditional deterministic conservative methods to the BEPU technical framework. The new standard makes standardized provisions for all process stages involved in BEPU analysis methods, including best estimate physical modeling, uncertainty quantification, condition enveloping, and result evaluation, aiming to enhance the scientific rigor, accuracy, and engineering practical value of PWR safety analysis. While strictly upholding the nuclear safety bottom line, it more accurately reproduces the true physical laws of accidents, effectively eliminates excessive conservatism, and addresses the industry pain point of balancing safety and economic viability in nuclear power plants.

The release of this standard will vigorously promote the application and dissemination of BEPU analysis methods in China's PWR nuclear power sector, elevate the overall level of nuclear safety analysis, and contribute to the high-quality development of China's nuclear power industry.