Analysis of Tank 30H (HTF-30-19-91, -92, -93), Tank 32H (HTF-32-19-94, -95, -96), and Tank 37H (HTF-37-19-97, -98, -99) Samples for Support of the Evaporator Feed Qualification and Corrosion Control Programs for the 3H-Evaporator

SRNL analyzed samples from Tank 30H, Tank 32H, and Tank 37H to support the Evaporator Feed Qualification and Corrosion Control Programs for the 3H-Evaporator system. The samples from Tanks 30H, 32H, and 37H all contain highly concentrated salt solutions with sodium concentrations ranging from 13.7 M to 17.1 M except for the Tank 32H surface sample with a sodium concentration of 4.38 M. Hydroxide is the dominant anion in all of the samples followed by nitrate and nitrite. Only the two samples from Tank 32H indicate any significant stratification of solution composition in the tanks with the surface sample much more dilute than the VDS. The surface sample and the VDS from Tank 30H are both generally more concentrated than the previous samples from the tank. The surface sample from Tank 32H is much more dilute than the previous surface sample while the Tank 32H VDS is slightly more concentrated than the previous VDS. The Tank 37H surface sample shows higher concentrations for most species than measured in the previous sample. The Tank 37H VDS has a similar sodium concentration to the previous sample with higher hydroxide, nitrite, and aluminate, and lower nitrate and carbonate concentrations. The difference between the sum of the major cations versus the sum of the major anions is quite high for the surface samples from Tank 30H and Tank 37H (~ 18%) while the difference is <5% for the VDS from each of these tanks. The two Tank 32H samples show a difference between the sum of the major cations versus the sum of the major anions of 9-10% indicating reasonable data quality. The silicon concentrations measured in the VDS and surface samples from Tank 30H, Tank 32H, and Tank 37H were all below detection.