Adsorptive separation of Kr from Nsub(2). Part I

Results of a chromatographic study of the adsorption of Nsub(2) and Kr on several molecular sieve adsorbents are reported. The objective was to find a suitable adsorbent for the removal of traces of radioactive Kr from the off-gas from nuclear fuel reprocessing facilities. Of the adsorbents examined, de-aluminated H-mordenite shows the highest selectivity for Kr relative to Nsub(2) and appears to be a promising adsorbent for this separation. The presence of traces of NOsub(2), a likely impurity in the off-gas, was found to suppress the adsorption of Nsub(2) more than that of Kr, thereby increasing the separation factor (αsub(Kr/Nsub(2)) approximately 12). In most of the adsorbents investigated, intracrystalline diffusion was too fast to measure but for Nsub(2) in H-mordenite, intracrystalline resistance was found to be significant and strongly dependent on the initial dehydration temperature