Analysis of the layout and shielding effectiveness of medical accelerator vaults
10.13491/j.issn.1004-714X.2025.02.010
- VernacularTitle:医用电子加速器机房布局和屏蔽效果分析
- Author:
Yajing SONG
1
;
Zengyun NIU
2
;
Yongzhong MA
3
;
Shihua TAO
1
;
Zechen FENG
3
Author Information
1. Beijing Betalab Technology Detection Co., LTD, Beijing 100013 China.
2. Institute of Radiation Medicine, ShandongAcademy of Medical Sciences, Jinan 250117 China.
3. Beijing Center for Disease Control and Prevention, Beijing 100013 China.
- Publication Type:OriginalArticles
- Keywords:
Medical accelerator;
Vault layout;
Shielding
- From:
Chinese Journal of Radiological Health
2025;34(2):204-208
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the layout and shielding effectiveness of medical accelerator vaults, and to provide a reference for the layout, shielding design, and optimization of protection of medical accelerator vaults. Methods Four medical accelerator radiotherapy vaults were selected. The layouts of these vaults were compared with the layout requirements in the radiation therapy protection standards. For each vault, the dose rates at four points of interest outside the shielding were calculated, including the primary shielding area, secondary shielding area, maze outer wall, and lateral shielding area. These values were then compared with the actual measurements obtained using a dose rate meter. Results All four vaults were located on the ground floor of the building and included a maze, with the auxiliary rooms all placed outside the treatment rooms. However, one vault was not located at one end of the building, and in another vault, the control room was exposed to direct irradiation of the useful beam. The calculated dose rates outside the primary shielding area ranged from 0.04 μSv/h to 0.62 μSv/h, while the measured values ranged from 0.10 μSv/h to 0.66 μSv/h, with the measured values being higher than the calculated ones. The calculated dose rates outside the secondary shielding area ranged from 0.0005 μSv/h to 0.12 μSv/h, those outside the maze outer wall ranged from 0.06 μSv/h to 0.18 μSv/h, and those outside the lateral shielding area ranged from 0.009 μSv/h to 0.15 μSv/h; the measured values were all below the detection limit. Conclusion Inadequate layouts were observed in some of the accelerator vaults. The calculated and measured dose rates at points of interest outside the vaults were both significantly lower than the shielding protection requirements in standards, indicating that the shielding designs were overly conservative. Construction units should follow the principle of optimization of radiation protection to design the layout and shielding reasonably and pay attention to the underestimation of dose rates outside the primary shielding caused by the tenth value layer.
