某有色金属有限公司职业病危害放射防护控制效果评价

目的评价某有色金属公司的γ射线装置的职业病危害放射防护控制效果,并提出有效的防护措施建议。方法根据职业病危害控制效果评价相关标准以及该公司的选矿厂特点,现场检测密封源γ射线辐射强度、核查放射防护设施及安全防护措施现状,评价放射防护效果。结果该有色金属有限公司的选矿厂现有5台密封源γ射线浓度计,活度分别是0.37、0.185、0.928、3.7、3.7GBq。密封放射源137Cs均放置在固定铅罐内并上锁,设置屏蔽挡板。检测5台γ射线源仪外围辐射剂量,100cm处的周围剂量当量率H*控制值分别为0.02、0.11、0.04、0.17、0.39μSv/h。磨浮5074球磨机溢流泵管道处剂量当量率0.39μSv/h,不符合《电离辐射防护与辐射源安全基本标准》中对γ射线源仪表外围辐射的剂量<0.25μSv/h的控制要求,其余均符合标准。结论该公司放射防护设施的防护效果较好,安全防护措施有效,基本达到国家法律、法规、标准的要求。在正常运行情况下,能够预防和控制潜在放射照射的发生。

Effectiveness Evaluation of Occupational Hazards Control Measures of Radiation Protection in a Nonferrous Metals Company

Objective:To evaluate the radiation protection control effect of the gamma-ray device for occupational hazards in a nonferrous metals company,and put forward effective suggestions about protection measures.Methods:According to the relevant standards for the evaluation of occupational disease hazards and the characteristics of the company’s ore dressing plant,detect the radiation concentration at the site of radiation protection facilities of sealed source gamma-ray concentration meter and check the current situation of radiation protection facilities and safety protection measures.In addition,the protection effects and various measures of engineering facilities are analyzed and evaluated.Results:There were currently 5 sealed source γ-ray concentration meters in the concentrator of the nonferrous metals company.Their activities were 0.37,0.185,0.928,3.7 and 3.7 GBq respectively.The sealed radioactive source 137Cs were all placed in the fixed lead tank and locked,and the shielding baffle and the warning sign of "beware of ionizing radiation" were set up.The company did not distribute personal radiation protection articles such as personal dosimeter to patrol workers who may be exposed to radiation.For five gamma-ray concentration meters,the control values of 100cm ambient dose equivalent rate were 0.02,0.11,0.04,0.17 and 0.39μSv/h respectively.The concentration meter at the overflow pump pipe of mill float 5074 ball mill did not meet the control requirements of "Basic Standard for Protection against Ionizing Radiation and Safety of Radiation Sources" for the dose of peripheral radiation of γ-ray source instruments less than 0.25μSv/h,while the rest met the standards.Conclusions:The radiation protection facilities of the company had good protection effect,and the safety protection measures were effective,basically meeting the requirements of national laws,regulations and standards.Under normal operation conditions,the occurrence of potential irradiation can be prevented and controlled.