核电机组二回路清洁是机组启动前的一项重要工艺,其工艺比较成熟,但目前尚无高温气冷堆二回路清洁相关标准和清洁工艺.本文根据高温气冷堆二回路系统特点和设备材质,参考火电机组热力系统和压水堆二回路清洁工艺,从理论和工程经验的角度对高温气冷堆二回路清洁做了可行性研究,最终确定了由清洁安装、化学清洗、二回路整体水冲洗相结合的二回路清洁工艺.通过对比人工清洁、蒸汽吹扫和化学清洗这3种工艺的可行性发现,高温气冷堆主蒸汽管及高旁管道清洁工艺只能通过化学清洗工艺来实现,清洗后需用pH值9~10的除盐水对清洗系统进行大流量水冲洗.%Cleaning the secondary circuit in nuclear power plants is an important process before the unit starting. Cleaning technologies for the secondary circuit of a pressurized water reactor (PWR) are relatively mature, but the ones for the secondary circuit in the high temperature gas-cooled reactor (HTGR) are lack of standards and processes. Thus, according to the system features and equipment materials of the secondary circuit in the HTGR, feasibility research on the cleaning process was conducted from the aspects of theory and engineering experience, by referring the cleaning processes for thermal power plant systems and PWR secondary circuits. Finally, a combined cleaning process was determined, which comprises cleaning installation, chemical cleaning and the secondary circuit overall water flushing. By comparing the feasibility of the three processes of manual cleaning, steam purging and chemical cleaning. Through comparing the feasibility of manual cleaning, steam blowing and chemical cleaning, it proved that the main steam pipe and high pressure side pipe cleaning process can only be realized by chemical cleaning process. After cleaning, the system should be washed with a large flow of water flushing using demineralized water (pH 9~10).
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