CRUD REMOVAL PERFORMANCE WITH ION-EXCHANGE RESINS IN BWR PLANTS

It is needless to say that one of the most important roles of the cond ensate demineralizer in Japanese boiling water reactors (BWR) is to el iminate such impurities during accidental occurrence of sea water leak age from condensate cooling system, Ion exchange resins packed in cond ensate demineralizer have also been expected to decrease crud, or corr osion products (CP) in condensate water in order to finally reduce act ivated corrosion products (ACP) in the reactor coolant loop. It is per ceived that crud removal ability of a condensate demineralizer has bee n improved year by year. And we call this phenomenon as ''Aging Effect ''. Typical property changes of aged cation exchange resin consisted o f an increase of water retention capacity and a change of surface text ure. Based on these findings, we formulated a new concept and develope d new gel type ion exchange resins for the better crud removal. The re sults from column tests using actual condensate water for approximatel y three years and full scale test at an actual condensate polisher fro m Sep. 1993 showed that a gel type cation exchange resin having 6% cro sslinkage produced excellent crud removal performance and low leaching rate of total organic carbon.