核级阀门非金属部件的延寿评估研究

Aging Life Research and Evaluation for In-service Nuclear Power Cables in High-temperature Hot Spot Areas

核级阀门的服役状态关系着核电厂的安全稳定运行,正常服役过程中依据设备鉴定管理要求定期实施短寿命部件更换,以维持阀门鉴定状态的有效性。本文针对某核级阀门旋塞衬套,开展鉴定寿命再评估,以期实现对短寿命设备部件的延寿与更换周期优化。本文全面分析了阀门旋塞衬套的老化机理,基于行业通用的寿命评估模型,通过比对实际服役参数与初始鉴定参数,挖掘阀门旋塞衬套的鉴定寿命裕量,并通过老化试验和状态监测对理论评估寿命并进行验证和校核。经评估,该阀门旋塞衬套鉴定寿命延长5倍以上。核电厂将其更换周期延长至原来的4倍,阀门运行良好。研究表明,通过时限老化分析方法对EQ设备部件开展鉴定寿命再评估,在保证安全的前提下,优化EQ设备部件的更换周期,可提高核电厂运行的经济性。

The service status of nuclear valves is related to the safe and stable operation of nuclear power plants.In the normal service process,short-life parts are replaced regularly according to the requirements of equipment qualification management to maintain the effectiveness of the valve qualification status.The paper conducts the life reevaluation of a short-lived non-metallic valve plug sleeve in a nuclear power plant,with the aim of optimizing its lifespan and replacement cycle.With the aging mechanism of the plug sleeve comprehensively analyzed,the paper excavates the qualification life margin of the plug sleeve by comparing actual service parameters with initial qualification parameters basing on industry wide life assessment models,and the theoretical evaluation life is verified and checked by aging test and condition monitoring.After evaluation,the service life of the plug sleeve has been extended by more than 5 times with its replacement cycle extended to four times the original.Research has shown that conducting life reevaluation of EQ equipment through reasonable methods,while ensuring safety,can greatly improve the economic efficiency of nuclear power plant operation by optimizing the replacement cycle of EQ equipment.