Pilot-Scale Grout Production Using a Simulated Low-Level Waste: Process Description and Product Characterization.

摘要

A US Department of Energy (DOE) program is under way at the Hanford Site Richland, Washington, to convert the low-level fraction of selected liquid radioactive wastes to a cementitious grout form for near-surface disposal. Grout slurry, consisting of a mixture of liquid waste and a solids blend, will be pumped to near-surface disposal vaults where it will harden, thereby immobilizing the waste. A pilot-scale test was conducted in July 1986 to assess the effectiveness of the grouting operations and to characterize grout produced with pilot-scale equipment and disposed of in a monolithic form. The objectives of the pilot-scale test were to determine the homogeneity of the grout produced under conditions similar to those planned for the GTF, to evaluate performance of candidate grout processing equipment for the GTF, and to evaluate properties of grout produced during continuous operation over an extended time period and cured in a large monolith. The first waste stream to be processed in the GTF is called Phosphate/Sulfate Waste (PSW). The phosphate waste is from decontamination of the cooling system at N Reactor using a commercial solution containing phosphoric acid as the principal ingredient. The sulfate waste was produced during regeneration of ion-exchange resins with sulfuric acid. Each of these wastes are neutralized with sodium hydroxide, resulting in an aqueous waste containing sodium phosphate and sodium sulfate. (ERA citation 14:000262)