Pérez López B, Navarro J F, López M A
Whole Body Counter, Internal Dosimetry Service, Radiation Dosimetry Unit (CIEMAT), Avda. Complutense 40, Madrid, Spain.
Radiat Prot Dosimetry. 2018 Dec 1;182(2):171-176. doi: 10.1093/rpd/ncy045.
Iodine-131 is one of the main concerns from the point of view of radiological protection in a short term after a nuclear accident. The WBC Laboratory of CIEMAT has developed a methodology for in vivo monitoring of radioiodine in the thyroid of exposed individuals in case of emergency. Thyroid-neck phantoms of different sizes are required for calibrating the detection systems in appropriate counting geometries for the measurement of exposed population. A Low-Energy Germanium (LEGe) detector and a Fastscan Counter were calibrated using a set of thyroid phantoms fabricated by CIEMAT. Each neck phantom consists of a Lucite cylinder with a vial source of 131I. Counting efficiencies depending on age and thyroid sizes were obtained to be used to determine the activity of 131I in internally contaminated people. DL of 131I varies with the age, being in the range of 5-8 Bq for the LEGe detector and 26-42 Bq for the Fastscan. Detection of intakes resulting in Committed Effective doses far below 1 mSv are guaranteed for thyroid monitoring in a few days after the accidental exposure assuming a scenario of acute inhalation or ingestion of 131I by members of the public.
从核事故后短期内辐射防护的角度来看，碘-131是主要关注点之一。CIEMAT的白细胞实验室开发了一种方法，用于在紧急情况下对受照射个体的甲状腺进行体内放射性碘监测。为了在适当的计数几何条件下校准检测系统以测量受照射人群，需要不同尺寸的甲状腺颈部模型。使用CIEMAT制造的一组甲状腺模型对低能锗（LEGe）探测器和快速扫描计数器进行了校准。每个颈部模型由一个装有131I瓶源的有机玻璃圆柱体组成。获得了取决于年龄和甲状腺大小的计数效率，用于确定体内受污染人员体内131I的活度。131I的探测下限随年龄而变化，对于LEGe探测器在5 - 8贝克勒尔范围内，对于快速扫描计数器在26 - 42贝克勒尔范围内。假设公众成员急性吸入或摄入131I的情况，在意外照射后的几天内对甲状腺进行监测可保证检测到导致待积有效剂量远低于1毫希沃特的摄入量。
