Some aspects of radiation protection in radionuclide therapy departments

The paper presents the data that allow calculate the attenuation factors in lead, tungsten and concrete of various thicknesses or the thickness of shielding made of these materials for a given attenuation factor for the spectra of gamma radiation of 131 I and 177 Lu radionuclides. Using these data the effectiveness of the protection of supporting equipment (portable containers, shielded syringes, etc.) and the possible doses of external radiation of medical personnel in the radionuclide therapy department were calculated. It is shown that there are short-term operations in the production process when a radiation source (container with a capsule with activity, syringe with activity), being near the body of a medical worker, creates a significant dose rate. For this reason the annual individual dose of external exposure of a medical worker can approach or exceed 1/3 of the dose limit. Calculation of the attenuation of 131 I gamma radiation by stationary shield showed that the thickness of walls and floors made of concrete 200 – 400 mm will ensure that the permissible values of the dose rates of gamma radiation in the air do not exceed at annual turnover of activity in the radionuclide therapy department of ~ 3.3 · 10 12 Bq.