Evaluation of analytical results on DOE Quality Assessment Program samples

Criteria were developed for evaluating the participants' analytical results in the DOE Quality Assessment Program (QAP). Historical data from previous QAP studies were analyzed using descriptive statistical methods to determine the interlaboratory precision that had been attained. Performance criteria used in other similar programs were also reviewed. Using these data, precision values and control limits were recommended for each type of analysis performed in the QA program. Results of the analysis performed by the QAP participants on the November 1983 samples were statistically analyzed and evaluated. The Environmental Measurements Laboratory (EML) values were used as the known values and 3-sigma precision values were used as control limits. Results were submitted by 26 participating laboratories for 49 different radionuclide-media combinations. The participants reported 419 results and of these, 350 or 84% were within control limits. Special attention was given to the data from gamma spectral analysis of air filters and water samples. Both normal probability and box plots were prepared for each nuclide to help evaluate the distribution of the data. Results that were outside the expected range were identified and suggestions made that laboratories check calculations, and procedures on these results. 6 tables