Automation of statistical analysis in the WIPP hazardous waste facility permit for analytical results from characterization

One goal of characterizing, processing, and shipping waste to the Waste Isolation Pilot Plant (WIPP) is to make all activities as efficient as possible. Data management and repetitive calculations are a critical part of the process that can be automated, thereby increasing the accuracy and rate at which work is completed and reducing costs. This paper presents the tools developed to automate statistical analysis and other calculations required by the WIPP Hazardous Waste Facility Permit (HWFP). Statistical analyses are performed on the analytical results on gas samples from the headspace of waste containers and solid samples from the core of the waste container. The calculations include determining the number of samples, test for the shape of the distribution of the analytical results, mean, standard deviation, upper 90-percent confidence limit of the mean, and the minimum required Waste Acceptance Plan (WAP) sample size. The input data for these calculations are from the batch data reports for headspace gas analytical results and solids analysis, which must also be obtained and collated for proper use. The most challenging component of the statistical analysis, if performed manually, is the determination of the distribution shape; therefore, the distribution testing is typically performed using a certified software tool. All other calculations can be completed manually, with a spreadsheet, custom developed software, and/or certified software tool. Out of the options available, manually performing the calculations or using a spreadsheet are the least desirable. These methods rely heavily on the availability of an expert, such as a statistician, to perform the calculation. These methods are also more open to human error such as transcription or 'cut and paste' errors. A SAS program is in the process of being developed to perform the calculations. Due to the potential size of the data input files and the need to archive the data in an accessible format, the SAS program is being developed in conjunction with a Microsoft Access database. The database acts as a central repository for all of the input and output data, records the list of analytes, and provides a graphical user interface for the end-user. The additional benefit to this tool is the incorporation of other calculations. One calculation is the compilation of the volatile organic compound data from 55-gallon drums with rigid liners that will be compacted and placed into a 100-gallon drum. Another analysis addresses the total concentration of flammable VOCs for transportation requirements. Development of such software tools improves the productivity of the groups that perform these functions. (authors)