放射線作業環境における計算用PIMALファントムと現実的な眼球モデルを用いた臓器および実効線量評価

The female and male computational phantom with moving arms and legs (PIMAL) are useful models for the calculation of the effective doses to workers in radiological occupational settings. In this study, Monte Carlo N-Particle (MCNP) Version 6.2 is used with PIMAL phantoms to simulate exposure in nuclear and medical settings. The PIMAL phantoms, defined by mathematical representation of the human body, allow for detailed assessment of equivalent dose to organs. These values are converted to effective dose (E) using sex- and age-average tissue weighting factors from ICRP Publication 103. Initial simulations of monoenergetic photons, electrons, and neutrons in the anterior-posterior (AP) geometry show good agreement with comparable results in the literature, obtained using the ICRP adult reference voxel phantoms and PIMAL phantoms in the standard upright position. For nuclear power applications, effective dose rates () are estimated for workers contaminated by radionuclides and compared with personal dose equivalent rates at 0.07 mm depth, (0.07). Additionally, effective dose rates from neutron and gamma fields are calculated for personnel inside a CANDU-600 (CANada Deuterium Uranium) nuclear reactor at full-power. In medical applications, effective dose rates to staff exposed to positron emitters, either from injected patients or activated cyclotron targets, are also assessed. Across all scenarios, effective dose derived from PIMAL phantoms are consistent with operational dose quantities when available, supporting their use in dose assessment and radiation protection planning.