Analysis of Underground Storage Tank Waste Simulants by Fourier Transform Infrared Photoacoustic Spectroscopy

Abstract

Underground storage tank waste sludge from nuclear fuel processes is difficult to analyze because of the extreme heterogeneity, chemical reactivity, and radioactivity of the waste. Conventional methods of analysis typically require extensive sample handling procedures either to thin the sample or to separate components prior to analysis. These procedures are time consuming, require radiation containment cells, and increase the risk of radiation exposure to lab personnel as a result of the extensive handling. In this paper a method utilizing Fourier transform infrared photoacoustic spectroscopy to analyze hazardous underground storage tank waste with a minimal amount of sample and sample handling is discussed. The method was developed with the use of waste tank simulants that were obtained from the Westinghouse Hanford Company. Emphasis was placed on the determination of disodium nickel ferrocyanide, sodium nitrate, and sodium nitrite because of the concern for the potential of exothermic reactions occurring between oxidizers and ferrocyanide-containing compounds. This method also allows for the analysis of other ions of interest in waste processes such as sodium sulfate. A simple sample preparation method is also discussed which uses freeze drying to remove water from the simulants while maintaining a uniform sample for analysis.