核电站二回路水汽系统阳电导率超标原因的研究

Cause Analysis of Superstandard Cation Conductivity of NPP Secondary Water-Steam System

核电站二回路系统的水质控制与关键重要设备蒸汽发生器的运行寿命有着密切的关系。阳电导反映着二回路水中阴离子的含量,控制其在期望值内,更为重要。对某核电站二回路水汽系统阳电导率超标原因进行了分析,在对二回路水汽系统阴离子含量、总有机碳含量、可溶性气体进行分析的基础上,找出了阳电导率超标的两个原因:一是投切精处理阳床带入的气体,使阳电导率波动;二是补给水中有机物含量偏高,最终导致给水、主蒸汽阳电导率超标。为此,提出了减少气体带入量、去除补给水中有机物含量的解决方案。

The water quality control of secondary circuit system in nuclear power plant（NPP）is closely related with the service life of key equipment steam generator.And it is especially important to control the cation conductivity within the expected value,which indicates the anion content in secondary circuit water.This paper analyzes the causes of superstandard cation conductivity of a NPP secondary water-steam system.Based on the analysis of anion content in secondary water-steam system,total organic carbon content,and the soluble gas,two reasons are found out for superstandard cation conductivity：firstly,the in-flowing gas during the fine switching processing of cation exchange bed leads to cation conductivity fluctuations;secondly,the high content of organic matter in supply water results in water-steam superstandard cation conductivity.Therefore,the solution scheme is proposed to reduce the amount of in-flowing gas and remove the content of organic matter in supply water.