VITRIFICATION AND TESTING OF HANFORD PRETREATED HLW SLUDGE MIXED WITH FLOWSHEET QUANTITIES OF SECONDARY WASTES

摘要

Actual pretreated HLW samples along with flowsheet quantities of secondary wastes were vitrified to demonstrate the RPP-WTP projects ability to satisfy the HLW product ORP Phase B-1 contract requirements concerning chemical and radionuclide reporting, waste loading, identification and quantification of crystalline and non-crystalline phases, and waste form leachability. Chemical composition of two HLW glasses (i.e., elements {excluding oxygen} present in Concentrations greater than 0.5 percent by weight) were measured using ICP-AES of solutions generated by a KOH fusion and a Na_2O_2 fusion. The total waste percent oxide in the C- 104 glass (all waste oxides (exclusive of Si) not identified in Table TS- 1.1 of the contract) comes to 10.02 percent, which is greater than the required 8.0 percent. The total of Al_2O_3 + Fe_2O_3 + ZrO_2 for AZ-102 Melt 1 is 21.96 percent, which is greater than the required 21.0 percent. The inventory of radionuclides (in Curies) was measured for each glass. The total and fissile uranium and plutonium Content of each canister of waste glass were calculated and are: 1161.5 grams for C- 104, 642.1 grams for AZ- 102 Melt 1. After canister centerline cooling, no crystals were observed in the C- 104 sample by XRD, optical examination, and SEM analysis. XRD analysis combined with optical microscopy and SEM EDS results of the CCC heat-treated AZ- 102 Melt 1 glass sample indicated the presence of a crystalline phase at approximately 1 to 2 volume percent, most likely trevorite and chromite. The normalized lithium, sodium and boron 90 deg C PCT releases for the C-104 and AZ-102 Melt 1 glasses are: 1) (for lithium) 0.5 g/m~2 and 0.4 g/m~2; 2) (for sodium) 0.4 g/m~2 and 0.4 g/m~2; and 3) (for boron) 0.4 g/m~2 and 0.3 g/m~2; respectively. The HLW product testing results from the C-104 and AZ-102 glasses show that in all cases they meet ORP Phase B-1 contract specifications.