Iodine and fluorine separation method in reactor coolants

Primary coolants containing both of iodine and fluorine are passed through a column filled with active alumina to selectively separate and remove fluorine in the primary coolants. The active alumina acts as an anion exchanger under a pH of about 4 or lower, whereas it acts as a cation exchanger under a pH of about 10 or higher. Since both of iodine and fluorine are halogen elements and have similar chemical behavior, it is generally recognized that both of them are adsorbed to the anion exchanger. However, in a case of the primary coolants of the reactor, since the pH is controlled from 5 to 7.5, an adsorbing characteristic vary in the pH region thereby enabling to separate them. With such procedures, radioactive iodine as fissile radioactive nuclides which is important with respect to evaluation of the fuel integrity can accurately be measured. (T.M.)