Y-90 폐기물 차폐를 위한 납-아크릴 복합 구조 운반함의 제작 및 유효성 평가

초록

Yttrium-90 (Y-90) is a pure beta-emitting radionuclide widely used in radioembolization and targeted radionuclide therapy. As the clinical use of Y-90 continues to increase, the safe management of radioactive waste generated after treatment has become increasingly important. However, high-energy beta particles emitted from Y-90 can generate bremsstrahlung radiation during the shielding process, potentially increasing occupational radiation exposure to radiation workers. Therefore, this study aimed to develop a lead-acrylic composite shielding container and evaluate its shielding performance for the safe handling and transportation of Y-90 radioactive waste. The shielding performance was evaluated under three shielding conditions: a single acrylic shield, a single lead shield, and a lead-acrylic composite shielding structure. Surface contamination and surface dose rate were measured ten times under each condition. Normality was assessed using the Shapiro-Wilk test, and paired t-tests were performed to compare differences among shielding conditions.The surface contamination levels were 9.929 ± 1.253 Bq/cm2 for the acrylic shield, 0.635 ± 0.059 Bq/cm2 for the lead shield, and 0.401 ± 0.033 Bq/cm2 for the lead-acrylic composite structure. The corresponding surface dose rates were 9.235 ± 1.177 μSv/h, 0.595 ± 0.047 μSv/h, and 0.363 ± 0.016 μSv/h, respectively. All variables satisfied the assumption of normality (p > 0.05), and statistically significant differences were observed among all shielding conditions (p < 0.001). The lead-acrylic composite shielding structure demonstrated superior radiation reduction performance compared with both the single acrylic and single lead shields. In particular, the sequential shielding configuration, in which beta particles are initially attenuated by a low-Z material and residual radiation is subsequently absorbed by a high-Z material, was found to be effective. These findings suggest that the proposed lead-acrylic composite container may serve as an effective shielding solution for the safe management and transportation of Y-90 radioactive waste.

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