Engineering-Scale Demonstration of DuraLith and Ceramicrete Waste Forms

Abstract

To support the selection of a waste form for the liquid secondary wastes from the Hanford Waste Immobilization and Treatment Plant, Washington River Protection Solutions (WRPS) has initiated secondary waste form testing on four candidate waste forms. Two of the candidate waste forms have not been developed to scale as the more mature waste forms. This work describes engineering-scale demonstrations conducted on Ceramicrete and DuraLith candidate waste forms.Both candidate waste forms were successfully demonstrated at an engineering scale. A preliminary conceptual design could be prepared for full-scale production of the candidate waste forms. However, both waste forms are still too immature to support a detailed design. Formulations for each candidate waste form need to be developed so that the material has a longer working time after mixing the liquid and solid constituents together. Formulations optimized based on previous lab studies did not have sufficient working time to support large-scale testing. The engineering-scale testing was successfully completed using modified formulations. Further lab development and parametric studies are needed to optimize formulations with adequate working time and assess the effects of changes in raw materials and process parameters on the final product performance. Studies on effects of mixing intensity on the initial set time of the waste forms are also needed. v SummaryThe Hanford Site in southeast Washington State has 56 million gallons of radioactive and chemically hazardous wastes stored in 177 underground tanks (DOE 2010). The U.S. Department of Energy (DOE), Office of River Protection, through its contractors, is constructing the Hanford Tank Waste Treatment and Immobilization Plant (WTP) to convert the radioactive and hazardous wastes into stable glass waste forms for disposal. Within the WTP, the pretreatment facility will receive the retrieved waste from the tank farms and separate it into two treated process streams. These waste streams will be vitrified, and the resulting waste canisters will be sent to offsite (high-level waste [HLW]) and onsite (immobilized lowactivity waste [ILAW]) repositories. As part of the pretreatment and ILAW processing, liquid secondary wastes will be generated that will be transferred to the Effluent Treatment Facility (ETF) 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 (IDF).To support the selection of a waste form for the liquid secondary wastes from WTP, Washington River Protection Solutions (WRPS) has initiated secondary-waste-form testing work at Pacific Northwest National Laboratory (PNNL). In anticipation of a down-selection process for a waste form for the Solidification Treatment Unit to be added to the ETF, PNNL is conducting tests on four candidate waste forms for stabilizing and solidifying WTP liquid secondary wastes:• Cast Stone Portland-cement-based waste form• Ceramicrete phosphate-b...

Microanalysis of Primary Biological Particles from Model Grass over Its Life Cycle

“…These magnesium potassium phosphate cements (MKPCs) are also described as "chemically bonded phosphate ceramics (CBPCs)" 184 or by the trade name "Ceramicrete" and have been extensively developed and trialed in the United States and Russia for conditioning of various challenging nuclear wastes, 185 including plutonium-contaminated ash; 174 heavy-metal and radium wastes; 178 99 Tc-bearing wastes, using SnCl 2 as a reductant; 177 liquid Hanford vitrification wastes; 186 and Mayak salt wastes. 187 Alongside this application, other MKPC patents have been granted to Wagh, Singh, and co-workers, 188−190 including for sprayable compositions and oil-field applications.…”

Recent Progress in Chemically Bonded Phosphate Ceramics

“…Several studies have been conducted in demonstrating immobilization of these waste streams using CBPCs [85][86][87][88]. Notable and detailed analysis among these was done in a collaborative project between Argonne, Vernadsky Institute of Radiochemistry in Moscow, and Production Research at Mayak, a nuclear waste facility in Russian Federation, which also has stored similar waste Figure 10.…”

“…Initial study was with simulated waste streams and success of this study led the scientists to tackle actual waste streams. Reference [88] contains details of the methodology, nature of the waste streams, additives in the CBPC formulations to immobilize difficult contaminants, properties of the waste forms, and their performance.…”

“…Table 4 lists the composition of each of the waste stream. Details of adding these stabilizers are described in the paper [88].…”

“…Table 6 lists the waste loading in the final waste forms and their physical properties. All results are reproduced from [88].…”