Patent Number: 
Section: claims

1. An apparatus for deionizing water, comprising: a secondary cooling water system for a PWR nuclear power plant which contains in the system a steam generator and a condenser, and which has a mixture of an anion exchange resin and a gel-type cation exchange resin having a crosslinking degree of about 12 to 16% therein. 2. An apparatus of  claim 1  wherein the anion exchange resin and the cation exchange resin forms a bed. claim 1 3. An apparatus of  claim 1  wherein the cation exchange resin has a crosslinking degree of about 14%. claim 1 4. An apparatus of  claim 1  wherein the cation exchange resin comprises a plurality of particles having a substantially uniform particle diameter. claim 1 5. An apparatus of  claim 1  wherein the secondary cooling water system further comprises a prefilter in an upstream of the mixture. claim 1 6. An apparatus of  claim 5  wherein the prefilter comprises at least one of a filter assembly containing hollow-fiber membranes, a filter assembly containing a precoatable filter element and a filter assembly containing a pleated, filter element. claim 5 7. An apparatus of  claim 1  wherein the mixture of the anion exchange resin and the gel-type cation exchange resin has a rate of elution of a total organic carbon of less than 0.03 g-TOC/m 3 -MR/hr. claim 1