Status and quality of radiation measurements. food and human urine. Preliminary report 1972-75

As part of the radiation quality assurance program conducted by the U.S. Environmental Protection Agency, calibrated radionuclide solutions are distributed to participating laboratories for instrument calibration and yield determinations. Laboratory performance studies involving the analysis of radionuclides in environmental media are also conducted. A summary is given of the results for the food and human urine cross-check programs for 1972-1975. For tritium, which was the least difficult to analyze, eighty-two percent of the laboratories were within the control limits for accuracy and ninety-nine percent within the control limits for precision over the 3-year period. For strontium-89, and most difficult to analyze, thirty-three percent were within the accuracy control limits and seventy-seven percent within the precision control limits