15MV医用电子加速器机房放射防护设计研究

Study of Radiation Protection Design for 15MV Medical Electron Accelerator Room

目的探讨某15 MV医用电子加速器机房放射防护设计的科学性,提出具体的防护建议和改进措施,从而保障放射治疗职业人员和公众的辐射安全。方法依据国内外相关技术规范和标准,对机房屏蔽及排风设计进行复核、计算,将计算结果与设计内容进行比较分析。结果机房墙体的屏蔽计算厚度(混凝土)为:西墙1300 mm、北主墙2400 mm、北副墙1200 mm、迷路口后东墙1200 mm、迷路墙后东墙1300 mm、南主墙2700 mm、南副墙1400 mm、机房顶2900 mm、机房副顶1600 mm;南、北主防护墙和主防护顶计算宽度分别为3500 mm、3700 mm;机房通风次数为0.06次/h。结论机房北主墙、北副墙、东墙的屏蔽厚度和主墙的屏蔽宽度符合标准要求,机房南主墙、南副墙、西墙、机房顶、机房副顶的屏蔽厚度和通风换气次数达不到标准要求。

Objective To explore the scientificalness of the radiation protection design of the 15MV medical electron accelerator room to guarantee the radiation safety of the medical staff and the public in radiotherapy, and provide specific suggestion and improvement measures. Methods According to the relevant domestic and foreign technical specifications and standards, review and calculate the design of shield and ventilation, comparing and analyzing the calculation results and design contents. Results The calculated thicknesses of room shield wall （concrete） are 1300 mm of west wall, 2400 mm of north main wall, 1200 mm of north side wall, 1200 mm of east wall behind the maze opening, 1300 mm of east wall behind the maze wall, 2700 mm of south main wall, 1400 mm of south side wall, 2900 mm of room main roof, 1600 mrn of room side roof. The width of south and north main shield wall and room main roof are 3500 mm and 3700 mm, the calculated ventilation rate of room are 0.06 times/h. Conclusion The shield thicknesses of north main wall, north side wall, east wall and the shielding width of main wall can meet the standards request, but the thicknesses of south main wall, south side wall, west wall, main roof, side roof and the ventilation rate of accelerator room can not.