Product of resin breakdown:
Another product of resin breakdown, [R - CH2N(CH3)2], is an amine along with exchange capabilities considerably less than the real form of the resin. Therefore, both reactions lead to partial (or complete) loss of replace capability. The resin will be unfit for use if the temperature is sufficiently high, or if a lower temperature (but greater than 180ºF) is sustained for a long enough period. If the temperature becomes extremely high (greater than about 450º F), the polymeric base structure of the resin will decompose, creating a complex combination of organic oils and tars.
The preceding discussion concerned the decomposition of resins within their original forms. That should be remembering which if overheating occurs after the resin has been in operation for a few times, part of the resin will be in a different form because of the exchange procedure. Conclusion, a few of the previously erased impurities will be released to the coolant if decomposition occurs.
A number of changes are possible if overheating of resin occurs. Reactor coolant Cl- stages would possibly increase as an output of thermal breakdown and following release. Ion exchanger efficiency would be greatly decreased for same purpose. Radioactivity stages of the reactor coolant would increase since of the release of impurities collected and later released from the resin. pH would such as decrease since of the release of H+ ions from the resin complex and might cause acidic conditions in the reactor coolant if the temperature is enough (>250ºF). Since certain types of resin decompose at lower temperatures, pH may increase as a result of the release of TMA and be accompanied through a dead fish odor. Because of the consequences of overheated resin then stringent temperature limitations are necessary. The ion exchanger should be taken out of service instantly and the cause rectified if overheating occurs. The resin must be replaced prior to placing the ion exchanger back in service after overheating.