Estimated effective dose to the reference adult female anthropomorphic phantom (ICRP) from irradiation of topaz activated in a nuclear reactor

摘要: A Purpose: To estimate the effective dose to the reference female distribution resulting from the use of reactor-activated topaz gemstones as personal adornments and to evaluate their compliance with national and international radiological protection regulatory limits.Materials and Methods: Monte Carlo simulations were performed using the PHITS code and the ICRP 110 adult female reference voxel phantom. The PHITS implementation of the phantom was validated against ICRP 116 organ dose coefficients, with a mean deviation of 1.2%.Six neutron-activated topaz samples from Rondônia region, Brazil, were modeled considering their elemental composition and density. Gamma-ray spectra experimentally obtained after more than one year of decay were used together with nuclear decay data from ICRP Publication 107.Exposure scenarios simulated the use of earrings and necklaces under conservative and occasionaluse conditions. Effective doses were compared with the limits established by ANSN Standard 3.01 and with international reference levels proposed by the IAEA SSG-36 and European Commission Radiation Protection 146. Results: Photon emissions from the radionuclides 46 Sc and 54 Mn were identified as the main contributors to dose. Nevertheless, all calculated values remained below the annual limit of 10 μSv year -1 established by ANSN 3.01. Under the conservative exposure scenario, annual effective doses ranged from 0.02 to 0.13 μSv year -1 ; conversely, under occasional-use conditions, all estimated doses remained below 0.002 μSv year -1 . Conclusion: Activated topaz gemstones used as personal adornments do not represent a significant radiological risk under the investigated conditions. Although conservative scenarios exceeded the most restrictive international reference interval for consumer products, occasionaluse conditions remained within internationally recommended levels.