Radiological protection control at a cyclotron facility

Abstract

High energy cyclotrons in use by several decades for the production of radionuclides in the diagnosis of diseases have been applied, particularly to supply the short-lived products to nuclear medicine services. The cyclotrons operate at relatively high beam currents which result in high dose rates in the vaults and there is potential risk of acute exposure of personnel. The cyclotron staff was identified among the higher exposure groups in the Instituto de Pesquisas Energéticas e Nucleares – IPEN – CNEN/SP. The radiological protection staff has established a radiological protection program whose purpose is providing an adequate occupational worker protection system in agreement to national and international radiological protection standards. The goal of this paper is to review the characteristics of unusual events occurred in the workplaces at cyclotron facility during the year of 2007. In addition, another objective is also to relate the main causes of unusual events occurred in the workplaces that resulted some worker irradiation or workstation contamination. The data analysis included the radiological protection records and reports examination, provided by radiation protection supervisor, complemented by interviews with radiation protection technician and workers involved in the processes. It was verified that in the period of study occurred nine events. Improved technology and dosimetry systems, the use of dose mapping techniques, innovative approaches to task analysis and the application of management skills to the planning of maintenance work have all contributed to this success. A major gain has been made but continues procedures reviews to cyclotron group are recommended according to the ALARA program.