核电厂延期换料时定期试验频度调整的评估和论证

Evaluation and Demonstration of NPP Periodic Testing Frequency Based on Long-period Refueling

压水堆核电站在运行初期通常采用年换料的燃料管理策略(12个自然月),为提高其经济性,在确保核安全的前提下,可实行延期换料(18个自然月)的燃料管理策略.延期换料的采用不仅会导致堆芯设计和燃料设计发生变化,也会对相关运行文件的执行产生影响,特别是核电站安全相关系统和设备的定期试验.通过应用运行经验反馈和技术经验积累、设备可靠性分析和重要度指标、概率安全分析相结合的分析方法,对定期试验频度进行确定论和概率论的综合评估和论证,从而制定合理的试验频度来满足延期换料策略的要求,最终保证核电站更安全、可靠的运行.

The pressurized water reactor (PWR) adopts annual refueling (12 months) at the beginning of the operation usually.In order to increase its economy,the long-period (18 months) refueling management could be taken place in the condition of ensuring PWR safety.This management not only causes the modifications of core and fuel design,but also effects the operating documentations,such as periodic testing of the safety and safety-related systems.The using of feed-back of operating experience,equipments reliability,and probability safety analysis could estimate and demonstrate the modification for periodic testing frequency to matching the long-period refueling,so that the NPP safety and stability can be ensured.