摘要
目的通过调查与测量掌握医用回旋加速器固体废物的放射性水平。方法采用γ辐射剂量率仪测量废物在带屏蔽的暂存状态下以及废物裸露状态下周围环境的周围剂量当量率H*(10),采用便携式高纯锗γ能谱仪及无源效率刻度软件对废物进行核素分析及活度测量,并对结果进行评价。结果4家医院废物在带屏蔽暂存状态下,表面5 cm处周围剂量当量率H*(10)测值范围为80.6μSv/h^1.32 mSv/h;能谱分析结果显示医用回旋加速器放射性固体废物中含有的放射性核素主要为56Co、54 Mn、57 Co,其中56 Co活度最高,单次换下来的靶膜及固定圈等废物中56 Co活度达到107Bq级别。结论医用回旋加速器放射性固体废物的放射性水平较高,所含放射性核素半衰期较长,其辐射防护问题需得到足够重视。
Objective To acquaint the radioactive level of solid waste from medical cyclotron by investigation and measurement.Methods The dose equivalent rate H*(10)of waste in temporary storage with or without shielding were measured by gamma radiation dose rate meter.The nuclide analysis and activity measurement of waste were carried out by a portable HPGeγspectrometer and the sourceless efficiency calibration software.Results Under temporary storage with shielding,the H*(10)of the four hospital wastes at 5 cm surface ranged from 80.6μSv/h to 1.32mSv/h.Energy spectrum analysis showed that the radionuclides in the solid wastes were mainly 56Co,54Mn and 57Co,among which the activity of 56Co was the highest.For each time of replacement,the activity of 56Co in the target membrane and fixed ring could reach the level of 107Bq.Conclusion Radioactivity level in the solid waste is high,and the half-lives of radionuclides are long.Sufficient attentions should be paid for the radiation protection of solid waste from medical cyclotron.
作者
许明发
林晨
林明媚
袁继龙
何叶娜
江岳
张巍
XU Mingfa;LIN Chen;LIN Mingmei;YUAN Jilong;HE Yena;JIANG Yue;ZHANG Wei(Guangxi Radiation Safety Supervision Station,Nanning 530222 China;National Institute for Radiological Protection,China CDC)
出处
《中国辐射卫生》
2019年第4期425-427,432,共4页
Chinese Journal of Radiological Health
