Condensate Polishing System for PWR Nuclear Power Plant

This paper provides summary of domestic in service nuclear power plant condensate polishing system (CPS) configuration, CPS is supplied for all domestic in service nuclear power plant and almost all above sub–critical fossil power plant, so condensate polishing system is necessary for PWR nuclear reactor. Based on USA industrial practice, the raw condensate for startup and normal operation is presented in this paper. Base on EPRI PWR nuclear reactor secondary water chemistry guideline for steam generator blowdown water quality, ion and water balance in secondary system, the effluent water quality for CPS is calculated. The condensate flow is proportional with electric power, during the plant startup operation, the electric power level from 0 to 30% to 50% to 100%, is longer time, i. e. condensate flow from 0 to 30% to 50% to 100%, is longer time. Before the plant electric power level 50% (or 30%), the impurity in condensate is purified, the makeup water for secondary system is demineralied water, the impurity level is lower than requirement, so 50% (or 30%) flow condensate polishing system is enough for startup operation. During the plant normal operation, condensate polishing system is in hot standby, if the condensate tube leak, condensate is deteriorated, the condensate polishing system need to be operated immediately, but CPS put in service from hot standby at least 5 minute. During this period, the units which is once–though cooled by sea water will be shutdown immediately with 2.71/h continuous condensate tube leakage, so full flow CPS is necessary for the units which is cooled by sea water, and it is better that one or two series put in service during normal operation other than all of them in hot standby. The units which is cooled by fresh water will be shutdown immediately with 2561/h continuous condensate tube leakage, for this level leakage, whichever 50%(30%) and 100% CPS, action level 2 will be preformed for the units, so 50%(30%) is enough for fresh water cooled units.