小型密封放射源主要是指γ料位计、核子称等使用的放射性活度小于37×109Ｂｑ的放射源。近年来,各地放射源丢失事故时有发生,对公众安全构成严重威胁,已引起人们的高度重视。近三年来苏州地区为加强环保工作先后关、停、并、转小水泥厂12家,使许多γ料位计闲置,带来了大量闲置 Small sealed radioactive sources mainly refers to the gamma level meter, nuclear said the use of radioactivity less than 37 × 109Bq radioactive sources. In recent years, accidental loss of radioactive sources from time to time has taken place, which poses a serious threat to public safety and has drawn great attention from people. In the past three years, Suzhou has successively shut down, stopped and transferred 12 small-scale cement factories to strengthen environmental protection work. As a result, a large amount of idle