The whole body counting experience on the internal contamination of radionuclides at IPEN/CNEN-SP

Abstract

The intake of radioactive material by workers can occur in the radiopharmaceuticals production, during the handling of radiopharmaceuticals in nuclear medicine and in bi ological and research laboratories. The members of staff occupationally exposed to radionuclides are routinely monitored for the purpose of quantitative assessment of internal exposure . Direct measurements of whole body and t hyroid contents provide an estimate of the activity of these radionuclides in the potentially exposed workers. The whole body measurements of the workers, trainees and visitors are routinely performed by the In Vivo Monitoring Laboratory (LMIV) of the Ener gy and Nuclear Research Institute (IPEN/CNEN SP). The frequency of measurements is defined by the Radioprotection Service (SRP) and the Dose Calculation Group of IPEN. For this purpose LMIV has two counters, whole body. NaI(Tl) (8x4”), and thyroid one, NaI (Tl) (3x3”). The system was calibrated in energy and efficiency, with calibration sources of Am 241, Co 60, Cs 137 and Eu 152 with gamma emissions between 59.54 and 1408.08 keV, positioned within Alderson Research Labs. anthropomorphic phantom. The backgro und measures were obtained of worker’s spectrum that wasn’t exposed occupationally yet. The concepts adopted in the HPS N13.30 Standard and proposed in ISO documents for standardization were used for activity measurements. During the period January 2014 to December 2018, approximately 3500 measurements had been carried in workers who develop tasks related to the production and research. The activities of the radionuclides and the workers’ tasks relationship had been evaluated.