核电厂埋地管道土壤腐蚀性评价及应用

Application and Evaluation of Soil Corrosivity for a NPP Buried Pipes

土壤腐蚀是造成核电厂埋地管道失效的重要影响因素之一,本文对某核电厂土壤电阻率、氧化还原电位、杂散电流干扰进行检测,并现场采集土壤试样,实验室对土壤pH值、含水量、氯离子、硫酸根离子含量等理化参数进行分析。首次采用土壤电阻法和综合指数法分别对某核电厂埋地管道所在的0~2m土壤层和0~10m土壤层的土壤腐蚀性进行评价,评价结果表明:0~10m土壤层的腐蚀性较0~2m土壤层的腐蚀性强,且两种方法评价土壤腐蚀性的结果一致。该研究成果可应用于其它核电厂埋地管道的土壤腐蚀性评价,为核电厂埋地管道的全寿期老化管理提供支撑。

Soil corrosion is an important factor leading failure of buried pipes in nuclear power plants(NPPs),A field study of soil resistivity,redox potential,stray current interference was carried out in a nuclear power plant,and soil samples collected at site were analyzed in laboratory for its physical and chemical parameters such as soil pH,water content,chlorine and sulphate content.Soil resistivity assessment method and comprehensive index assessment method were used to evaluate soil corrosivity for 0 to 2 meters and 0 to 10 meters deep soil layers in a nuclear power plant for the first time,and the evaluation results showed that the corrosivity of 0 to 10 meters deep soil layer was more than the 0 to 2 meters deep soil layer,and evaluation results of soil corrosion are consistent in both methods.The research result can be applied to the evaluation of soil corrosion of buried pipes in other NPPs,and providing support for the life-cycle aging management of NPPs buried pipes.