核工业某厂铀尾矿库补救行动剂量评价

DOSE ASSESSMENT OF REMEDIAL ACTION FOR URANIUM TAILING IMPOUNDMENT OF A NUCLEAR FACTORY

本文分析评价了某厂铀尾矿库补救行动计划中工作人员和公众所受照射的剂量。补救行动中工作人员的照射途径主要是吸入氡及其子体、吸入空气中悬浮的尾矿尘和直接 γ外照射。考虑可能的最大照射景象是 ,在工作时间内施工人员一直处于未覆盖的尾矿上 ,不考虑施工机械和设备对施工人员的防护作用 ,也不考虑其它防护措施的作用。剂量估算结果表明 ,工作人员所受的有效剂量为 6 .0 m Sv/ a。补救行动完成后 ,公众的照射分别考虑了正常和非正常情况下的照射。正常情况下 ,从尾矿库中析出的氡是对周围公众造成照射的主要途径 ,最大个人有效剂量为 0 .0 53m Sv/ a,80 km范围内公众的集体有效剂量为 1人·Sv/ a。非正常情况下 ,考虑了居住在尾矿库上、在尾矿库上从事农业活动、居住在掺有尾矿砂的建筑材料所建造的房屋中和在尾矿库上的短期活动 4种代表性的景象 ,其最大个人剂量为 2 7m Sv/

A large uranium tailing impoundment in China will be closure and remedial action have been planned.The remedial action will include shaping and covering the dam and beach in order to prevent the impoundment from damage and restrict spread of tailing sands and emission of radon.The paper presents the analysis and estimation of the exposure to workers for remedial action and to public after the remedial action.To estimate the exposure to workers,the pathway of inhalation of radon,tailing sands in suspension and external γ exposure were taken into consideration.The exposure scenario is considered as probably maximum exposure to the workers who work on the tailing pile without any protection measures,the dose is 6.0 mSv/a.Two situation for the exposure to public after remedial action were considered:normal and abnormal condition.For the normal condition,inhalation of radon emitted from impoundment is only the pathway to public for the exposure,and individual dose for critical group of public is 0.053 mSv/a,collective dose for population within 80 km is 1.0 man·Sv/a.For the abnormal conditions,four scenarios were considered,i.e. dwelling on tailing pile,farming on tailing pile,living in a house built by contaminated materials and some temporal activities on the pile.The scenarios of dwellings is living in a house on the pile and drinking contaminated water.The maximum individual dose is 27 mSv/a. (