In support of Hanford Tank Waste Treatment and Immobilization Plant (WTP) direct feed low-activity waste operations, this document seeks to provide a discussion on currently required radionuclide sample analyses and which, if any, are planned but may not be needed. The total number of analyses is more than 10,000 per year and, often, this analytical endeavor is difficult due to troublesome components. Such components cause issues due to low concentrations, difficulty of analysis, lack of standards, or other reasons. One of the main goals is to remove onerous or troublesome components that are present in low enough concentrations to not pose a threat of the resulting waste form being non-compliant if not measured. Additionally, if it can be demonstrated that the large number of analyses is not needed, then that will save hold times in operations, decrease the amount of money required for operations, and reduce potential exposure for plant staff or researchers.
Suggestions are provided for radionuclide analytes that may not be needed and can be safely estimated from process knowledge documented in the best basis inventory. The analytes recommended for removal were determined via calculations using batch feed estimates from the Tank Utilization Assessment of 2013. Approximately 750 feed estimates, representing waste compositions throughout the lifetime of the Hanford mission, were analyzed, and radionuclide concentrations were compared against established reporting and contractual limits as specified in the WTP contract. Analytes that were found to be consistently below the limits include many transuranic radionuclides and other radionuclides present in the waste in small concentrations. A total of 23 of the 44 radionuclides in the batch estimates were not significant in all batch feeds.