Plant engineering experience with primary water purification plants in nuclear power stations with pressurised and boiling water reactors

Ion exchangers are installed for purification purposes on both types of reactor - in ball-form in the case of the PWR and as resin powder deposits in the case of the BWR. An additional dearator is installed in the case of the PWR. With these units during reactor operation both the specified chemical values of the water and also the lowest possible activity levels are adhered to. The paper describes in particular the duties of the water purification systems at start up and shutdown of a reactor as well as the designs and methods of operation of such systems for both reactor types. (orig.)