Leachability of Decontamination Reagents From Cement Waste Forms.

Abstract

AbstractBrookhaven National Laboratory, in order to provide technical information needed by the U.S. Nuclear Regulatory Commission to evaluate the adequacy of near-surface disposal of decontamination wastes, has begun to study the leachability of organic reagents from solidified simulated decontamination wastes. Laboratory scale cement waste forms containing EDTA, picolinic acid or simulated (low oxidation metallic ion) decontamination reagent were leach tested. Samples containing an organic reagent on either mixed bed ion-exchange resins or anion exchange resins were tested. A fixed interval leach procedure was used, as well as the ANS 16.1 standard procedure. The leachability indices measured for the release of the acid from resin/cement composites are: 10.1 for EDTA on mixed bed resins; 9.1 for picolinic acid on mixed bed resins; 9.2 for picolinic acid on anion exchange resins; 8.8 for picolinic acid in forms containing simulated LOMI reagent on mixed bed resins and 8.7 for picolinic acid in forms containing simulated LOMI reagent on anion exchange resins. The leachability indices measured varied with leach time and the data indicate that a simple diffusion model may not be adequate for defining release from these waste forms.