Beyond contract compliance: Common problems found during validation of radioanalytical data

Abstract

In the United States today, legally defensible data is needed for environmental assessments, waste characterization, and dose assessments. A closer look at the raw data and interpretation of the results can reveal other problems that affect the data usability based on the project data quality objectives. The common problems include the following: incomplete sample dissolution, loss of volatile radionuclides during sample preparation, difficulties in aliquot subsampling during sample preparation, lack of a sample-specific chemical recovery mechanisms, use of an inappropriate sample-specific chemical recovery mechanism, not using enough of the sample-specific chemical recovery mechanism to obtain sufficient counting statistics for the recovery result, gamma-spectrometry misidentification, use of incorrect abundances or intensities, and incomplete separation of isotopes prior to alpha-spectroscopy analysis. These problems can result in the estimation or rejection of the results. Although most of these problems can be avoided, no improvement in their frequency has been noticed over time. This paper is written in an attempt to call attention to the typical problems in hopes that the contract laboratories as well as the government laboratories will review their practices to avoid these problems.