某项目核取样系统管线应力评定分析

Analysis of Stress Assessment of Pipeline in Nuclear Sampling System of a Project

核电站安全壳是重要的安全防御边界,确保取样管线穿过安全壳时的结构完整性及安全性十分重要。为了确保安全壳的气密性和完整性,会在安全壳机械贯穿件中设置贯穿件膨胀节。但是,安全壳机械贯穿件上设置的膨胀节会对取样管线的应力计算产生影响;而不同类型的机械贯穿件,其上面设置的膨胀节连接形式不同,因此,对管道应力计算时的影响也不相同。介绍了RCC-M规范对取样管线与安全壳机械贯穿件膨胀节焊接时的应力分析和评价方法,重点研究A型机械贯穿件上设置的膨胀节对取样管线应力分析的影响,并给出了考虑贯穿件膨胀节对管道应力计算影响后导致管线不能满足RCC-M时的优化方案。该研究对核电站设计人员有一定的参考价值。

The containment of nuclear power station is an important boundary of safety defense. It is very important to ensure the structural integrity and safety of the sampling pipeline when penetrating through the containment. In order to ensure the airtightness and integrity of the containment,expansion joints will be arranged in the mechanical penetration of the containment. However,the expansion joints arranged on the mechanical penetration of the containment will have an effect on the stress calculation of the sampling pipeline; And for different types of mechanical penetration,the type of connection of the expansion joint arranged on it is different,therefore,the influence on the stress calculation of the pipeline is also different. The methods of stress analysis and assessment by RCC-M code were introduced when welding the expansion joint of the sampling pipeline and mechanical penetration of the containment with focus on the research of the influence of expansion joint arrangement on the A-type mechanical penetration on the stress analysis of the sampling pipeline,and the optimization scheme was given when the pipeline fails to meet RCC-M after taking into account the influence of the expansion joint on pipe stress calculation. The present research provides certain reference for the designers of nuclear power stations.