Patent Number: 050826182
Section: claims

1. Method for modifying the concentration of boric acid in the form of soluble poison contained in cooling fluid of a primary circuit of a nuclear reactor, comprising the steps of (a) removing said cooling fluid from said primary circuit (1);  (b) monitoring said concentration of boric acid in said cooling fluid;  (c) as a function of said concentration of said cooling fluid, selectively passing all of said cooling fluid into at least one electrodialysis module, and alternatively passing only a first part of said cooling fluid into electrodialysis modules and a second part towards at least one reverse osmosis apparatus;  (d) adding an additive promoting dissociation of said boric acid to said cooling fluid when said cooling fluid leaves said primary circuit; and  (e) returning said cooling fluid into said primary circuit. 2. Method according to claim 1, wherein said additive is ammonia solution. 3. Method according to claim 2, including the step of readjusting the content of ammonia solution of said cooling fluid of said primary circuit upstream of said electrodialysis modules and of said reverse osmosis apparatus.