Final report for tank 241-C-204, auger samples 95-AUG-022 and95-AUG-023

Two auger samples from tank 241-C-204 (C-204) were submitted to the 222-S Laboratories for safety screening analyses, consisting of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and total alpha activity. Sampling and analysis requirements are presented in the Sampling and Analysis Plan (SAP) (which was adapted with minimal changes from the original Tank Characterization Plan. The Tank Characterization Plan was subsequently revised, and the sampling and analytical requirements were inadvertently deleted). The DSC results for all samples from the tank exceeded the action limit of 481 J/g. Secondary analyses [total organic carbon (TOC) and adiabatic calorimetry], as negotiated with the safety program, were performed. The TOC results also exceeded the action limit of 3 weight percent. However, the moisture content of the samples is between 50 and 60%, and the results of adiabatic calorimetry testing indicated that the sample material would not support a propagating exothermic reaction. Primary and secondary analytical results were reported previously. The 90-day report indicated that additional heat capacity and DSC tests would be performed to further interpret the adiabatic calorimetry results. However, the laboratory has not been able to successfully perform heat capacity tests at this time. Therefore, this report is being issued without these results to provide a permanent record of the analytical work to date. Should the laboratory acquire the capability of performing these tests in the future, the safety program should consider whether further analysis of the remaining C-204 samples is worthwhile. Organic speciation was also performed at the direction of the safety program. These analyses were performed by Battelle in the 329 Laboratory. These analyses were not performed to the controls in the SAP, but were performed to a Letter of Instruction. The results indicate that the sample tested had an extremely high concentration of tributyl phosphate. Some dibutyl phosphate was also present. Other organics were present in only trace quantities