Radiotracers in performance evaluation of nuclear grade resins Amberlite IRN-78 and Purolite NRW-8000

The present paper deals with evaluation of organic base nuclear grade anion exchange resins Amberlite IRN-78 and Purolite NRW-8000 by application of radioactive tracer isotopes 131I and 82Br. The evaluation was made on the basis of their performance in iodide and bromide ion-isotopic exchange reactions carried out under different experimental conditions like temperature and ionic concentration. It was observed that during iodide ion-isotopic exchange reaction at a constant temperature of 30.0 C, as the concentration of labeled iodide ion solution increases from 0.001 mol/L to 0.004 mol/L, the percentage of iodide ions exchanged increases from 70.10 % to 77.10 % for Amberlite IRN-78, which was higher than an increase of 63.90 % to 71.00 % as obtained for Purolite NRW-8000 resins. Also at a constant temperature of 30.0 C, using 1.000 g of ion exchange resins and 0.001 mol/L labeled iodide ion solution, the values of specific reaction rate (min-1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log Kd were calculated to be 0.280, 0.175, 0.049 and 11.4 respectively for Amberlite IRN-78 resin, which was higher than the values of 0.258, 0.160, 0.041 and 10.6 respectively as that obtained by using Purolite NRW-8000 resins. The identical trend was observed for the two resins during bromide ion-isotopic exchange reaction. The results of present investigation also indicate that during the two ion-isotopic exchange reactions, for both the resins, there exists a strong positive linear correlation between amount of ions exchanged and concentration of ionic solution; and strong negative correlation between amount of ions exchanged and temperature of exchanging medium. The overall results indicate that under identical experimental conditions, Amberlite IRN-78 resins show superior performance over Purolite NRW-8000 resins. (orig.)