Vitrification and Product Testing of C-104 and AZ-102 Pretreated Sludge Mixed with Flowsheet Quantities of Secondary Wastes

Abstract

SummaryThe U.S. Department of Energy (DOE) Office of River Protection (ORP) has acquired Hanford tank waste treatment services at a demonstration scale. The River Protection Project Waste Treatment Plant (RPP-WTP) team is responsible for producing an immobilized (vitrified) high-level waste (IHLW) waste form. Pacific Northwest National Laboratory, hereafter referred to as PNNL, has been contracted to produce and test a vitrified IHLW waste form from two Envelope D high-level waste (HLW) samples previously supplied to the RPP-WTP project by DOE.The primary objective for vitrifying the HLW samples is to generate glass products for subsequent product testing. The scope of the Vitrification and Product Testing has been divided into eight work elements: 1) Glass Fabrication, 2) Chemical Composition, 3) Radiochemical Composition, 4) Crystalline and Non-crystalline Phase Determination, 5) Release Rate (PCT), 6) Toxicity Characteristic Leaching Procedure (TCLP), 7) Total volatile organic and semi-volatile organic analyses (VOA and SVOA), and 8) WAPS, regulatory, and de-listing testing. The work presented in this report is from only the following 5 work elements: 1) Glass Fabrication, 2) Chemical Composition, 3) Radiochemical Composition, 4) Crystalline and Non-crystalline Phase Determination, and 5) Release Rate (PCT). These work elements will help demonstrate the RPP-WTP projects ability to satisfy the product requirements concerning, chemical and radionuclide reporting, waste loading, identification and quantification of crystalline and non-crystalline phases, and waste form leachability. Results from work elements 6 through 8, i.e. VOA, SVOA, dioxins, furans, PCBs, and total cyanide and sulfide analyses are reported in a separate document (Goheen et al., WTP-RPT-010).Two pretreated tank sludge samples, high-level wastes (241-C-104 and 241-AZ-102) hereafter referred to as C-104 and AZ-102 along with a HLW process simulant (know as the HLW Process Blank) were prepared as melter feeds for vitrification. Due to scheduling constraints and small initial sample size of the pretreated tank 241-AZ-102 sludge, this sample was divided into two samples that were vitrified separately (i.e. AZ-102, Melt 1 and AZ-102, Melt 2). The analyzed compositions of the pretreated C-104 and AZ-102 sludge wastes were used by Catholic University of America's (CUA) Vitreous State Laboratory (VSL) to determine the target glass composition.The two tank sludge samples, were processed through pretreatment chemical washing and leaching processes, and the pretreated sludges were converted to high-level waste (HLW) glass after flowsheet quantities of secondary wastes, i.e. Sr/TRU precipitate and Cs and Tc ion exchange eluants, generated from LAW supernatant pretreatment unit operations were added. Both sludge samples were processed through the following unit operations to simulate the RPP-WTP project flowsheet: 1) initial characterization; 2) washing; 3) leaching; and 4) filtration in a crossflow filtration system (Brooks et al., 2000a) (Brooks et al.,...