QUALITY OF RADIONUCLIDE ANALYSIS IN ENVIRONMENTAL SAMPLES

To supply Brazilian needs in the held of quality of radionuclide analy ses in environmental samples, the Institute for Radioprotection and Do simetry of the National Nuclear Energy Commission (IRD/CNEN) has begun a national intercomparison program (PNI) to encourage the development and optimization of analytical methodologies for radionuclide determi nation in environmental samples. Since its initiation, the PNI has pro moted eight intercomparison runs involving 221 studies in a total of 4 85 analyses. These studies consist of the determination of different r adionuclides in many kinds of environmental simulated matrices, like w ater, milk and filtered air. The total analytical performance reached by the 16 participant laboratories was: 73.7% good results (within all limits), 10.2% of results in the warning zone and 16.1% unacceptable results (out of the control limits). As was expected, the analytical p erformance of the laboratories had improved after their participation in the intercomparison runs, which emphasizes the importance of this c ooperative work.