Secondary Waste Form Down Selection Data Package ??? Ceramicrete

Cantrell, Kirk J. ; Westsik, Joseph H.

关键词: AR FACILITIES;    ANIONS;    AQUEOUS SOLUTIONS;    BINDERS;    CATIONS;    CERAMICS;    CHEMICAL REACTIONS;    FLUIDIZED BEDS;    MAGNESIUM OXIDES;    PHOSPHATES;    PHOSPHORIC ACID;    POROSITY;    POTASSIUM;    SLUDGES;    SOLID WASTES;    SOLIDIFICATION;    STABILIZATION;    TANKS;    WASTE FORMS;    WASTE PROCESSING;    HIGH-LEVEL RADIOACTIVE WASTES ceramacrete;    secondary waste form;    secondary waste;    chemically bonded phosphate ceramic;   

DOI  :  10.2172/1026623
RP-ID  :  PNNL-20681
PID  :  OSTI ID: 1026623
Others  :  Other: 830403000
Others  :  TRN: US1105480

学科分类：核能源与工程

美国|英语

来源: SciTech Connect

【 摘 要 】

As part of high-level waste pretreatment and immobilized low activity waste processing, liquid secondary wastes will be generated that will be transferred to the Effluent Treatment Facility on the Hanford Site for further treatment. These liquid secondary wastes will be converted to stable solid waste forms that will be disposed in the Integrated Disposal Facility. Currently, four waste forms are being considered for stabilization and solidification of the liquid secondary wastes. These waste forms are Cast Stone, Ceramicrete, DuraLith, and Fluidized Bed Steam Reformer. The preferred alternative will be down selected from these four waste forms. Pacific Northwest National Laboratory is developing data packages to support the down selection process. The objective of the data packages is to identify, evaluate, and summarize the existing information on the four waste forms being considered for stabilization and solidification of the liquid secondary wastes. The information included will be based on information available in the open literature and from data obtained from testing currently underway. This data package is for the Ceramicrete waste form. Ceramicrete is a relatively new engineering material developed at Argonne National Laboratory to treat radioactive and hazardous waste streams (e.g., Wagh 2004; Wagh et al. 1999a, 2003; Singh et al. 2000). This cement-like waste form can be used to treat solids, liquids, and sludges by chemical immobilization, microencapsulation, and/or macroencapsulation. The Ceramicrete technology is based on chemical reaction between phosphate anions and metal cations to form a strong, dense, durable, low porosity matrix that immobilizes hazardous and radioactive contaminants as insoluble phosphates and microencapsulates insoluble radioactive components and other constituents that do not form phosphates. Ceramicrete is a type of phosphate-bonded ceramic, which are also known as chemically bonded phosphate ceramics. The Ceramicrete binder is formed through an acid-base reaction between calcined magnesium oxide (MgO; a base) and potassium hydrogen phosphate (KH{sub 2}PO{sub 4}; an acid) in aqueous solution. The reaction product sets at room temperature to form a highly crystalline material. During the reaction, the hazardous and radioactive contaminants also react with KH{sub 2}PO{sub 4} to form highly insoluble phosphates. In this data package, physical property and waste acceptance data for Ceramicrete waste forms fabricated with wastes having compositions that were similar to those expected for secondary waste effluents, as well as secondary waste effluent simulants from the Hanford Tank Waste Treatment and Immobilization Plant were reviewed. With the exception of one secondary waste form formulation (25FA+25 W+1B.A. fabricated with the mixed simulant did not meet the compressive strength requirement), all the Ceramicrete waste forms that were reviewed met or exceeded Integrated Disposal Facility waste acceptance criteria.