钢铁企业辐射风险评估与控制对策研究

发布时间：2018-01-19 03:29

本文关键词： 钢铁企业放射源放射性活度放射防护个人剂量风险评估　出处：《武汉科技大学》2012年硕士论文　论文类型：学位论文

【摘要】：目的了解钢铁企业放射性物质及放射防护管理基本现状及历史放射性意外事故资料，掌握辐射环境剂量水平和个人吸收剂量水平，识别和掌握钢铁企业放射风险因素，定量评估放射风险水平，确定合理、可行的辐射风险预防控制对策措施和建议，以消除或减轻辐射危害，为企业做好放射防护工作提供科学依据。方法 1.辐射源调查及检测：以武汉钢铁公司为代表性企业，制定钢铁企业辐射基本情况调查检测表，对涉源单位名称、辐射源类型、放射性物质、放射活度或件数、用途、使用或闲置状况、职业环境水平、辐射管理制度等进行调查； 2.放射职业危害评定：制定辐射装置职业危害调查表，监测放射源工作现场放射剂量强度，对职业辐射暴露人员个人累积辐射剂量进行监测，调查暴露人员人口学资料、可能暴露机会、辐射事故可能情形、放射防护知识技能等信息； 3.辐射事故模型预测：采用放射事故调查表，收集武钢近10年辐射事故基本资料，通过GM(1,1)灰色模型对辐射事故进行预测，进而确定辐射风险主要类型和风险水平； 4.辐射风险评估：采用AS/NZS4360:2004风险评价指数矩阵法数学模型，在建立武钢辐射源数据库基础上，对辐射风险建立风险矩阵表，根据矩阵表中相对应的情况确定不同辐射风险的风险指数； 5.辐射风险管理措施：在辐射风险评估基础上，根据《中华人民共和国职业病防治法》、《中华人民共和国放射污染防治法》、GB18871-2002《电离辐射防护与辐射源安全基本标准》、 GB/T17982-2000《核事故应急情况下公众受照剂量估算的模式和参数》等法律法规和卫生标准，制定钢铁企业辐射安全管理制度，建立钢铁企业辐射风险事故应急预案。结果 1.截至2009年12月31日，武钢本部及鄂钢公司共有放射源332枚，青山本部企事业单位共使用X射线装置及医用加速器119台。企业所有放射源中，放射性活度范围0.0925GBq～1.85TGBq，总活度12.289TBq。核素类别主要为60Co、241Am、241Am-Be、85Kr、137Cs、3H-Ti；其中在用放射源185枚，总活度10.394TBq最大源为1.85TBq，最小源0.0925GBq，；库存放射源147枚，总活度1.895TBq，最大源0.185TBq，最小源0.185GBq。所有以Ⅳ类和Ⅴ类源为主，占全部放射源的91.27%。 2.环境剂量水平监测，源表面5cm处X-γ空气吸收率剂量为0.06-11.81μSv/h；100cm处总空气吸收剂量率范围为0.03-66.78μSv/h，源库周围空气剂量吸收率范围：0.11-0.14μSv/h，平均值：0.124μSv/h，均低于国家剂量限值标准。 3.对80名放射工作人员进行有效辐射个人剂量监测，年剂量范围在0.568mSv-6.130mSv之间，人平均年有效剂量为1.893mSv。87.5%的人员年均剂量都在2mSv以下，其中80%的人员年均剂量在1mSv以下。1.25%的人员年均剂量高于5mSv。集体剂量为151.410man·mSv，硅钢厂、冷轧厂、金结公司、质检中心、研究院年均剂量分别为3.032mSv、1.460mSv、2.438mSv、1.285mSv、1.757mSv (平均值为1.893mSv)。 4.自1980年代以来，武钢本部及鄂钢曾先后发生过4起放射源被盗、失控事件，7起废钢来料辐射剂量超标现象。近10年共发生7起放射性意外事故，事故级别全部为一般辐射事故。运用GM(1,1)得出预测模型对事故数据进行拟合，经检验Ck=0.2059，Pk=1.1000，模型精度较高。对2011年度进行事故预测，结果为0.94。即根据预测，如果不采取更有效的预防措施，2011年该车间内事故将为0.94起。 5.利用风险评估矩阵法对武钢放射风险事件进行识别，其大致可分为三类：放射源及放射性物质相关事故，，由生产实践活动所造成的放射风险事件，放射工作人员及公众人群意外照射事故。其中放射源丢失/被盗、放射性物质运输超标、废钢放射性污染三种风险因素风险水平为E-76(极大风险)，放射工作人员职业照射为H-56(高风险)。结论 1.武钢放射源环境辐射剂量水平低于国家剂量限值，但种类繁杂，使用频率高，存在安全隐患，放射防护工作须进一步完善； 2.各涉源单位环境辐射剂量水平和放射工作人员个人年均剂量低于国家剂量限值(20mSv/年)，其中硅钢厂人均年有效剂量水平和集体剂量水平最高； 3. GM(1,1)模型预测，如果不采取更有效的预防措施，2011年武钢事故仍可能有0.94起发生； 4.钢铁企业放射风险因素复杂、风险控制的难度大。制定针对性强的放射风险防控措施，具体包括健全管理组织机构，完善各项规章制度，加强辐射源防护，强化作业管理，普及放射工作人员防护意识及健康管理，定期检查监督系统和科学的事故应急处理机制，以保证企业安全生产是非常必要的。
[Abstract]:objective
Understand the iron and steel enterprises radioactive materials and radiation protection management of the basic situation and history of radioactive accident data, master the environmental radiation dose level and individual absorbed dose level, recognition and mastery of the iron and steel enterprises radiation risk factors, quantitative assessment of radiation risk level, determine the reasonable countermeasures and suggestions and feasible radiation risk prevention and control, to eliminate or reduce the radiation harm, provide scientific basis for enterprises to do the radiation protection work.
Method
The investigation and detection of 1. radiation source: Wuhan Iron and Steel Corporation as the representative enterprises, make investigation into the basic situation of iron and steel enterprises radiation detection table, the name of the related source units, the type of radiation source, radioactive substances, radioactivity and quantity, use, or use of idle status, occupation environment level, radiation survey management system;
2.: the development of occupation hazard evaluation radiation radiation device occupation hazards monitoring work on-site questionnaire, radioactive radiation dose intensity, exposure of personal cumulative radiation dose monitoring of radiation exposure to personnel occupation, investigation of demographic data, may be exposed to radiation accident, where possible, radiation protection knowledge and skills of information;
3., the prediction of radiation accident models: using the radiation accident questionnaire to collect the basic data of radiation accidents in recent 10 years in WISCO, and predict the radiation accidents by GM (1,1) grey model, and then determine the main types and risk levels of radiation risk.
4., radiation risk assessment: Based on the mathematical model of AS/NZS4360:2004 risk assessment index matrix method, based on the establishment of the radiant source database of WISCO, we set up the risk matrix for radiation risk and determine the risk index of different radiation risk according to the corresponding situation in the matrix table.
5. radiation risk management measures in radiation risk assessment basis, according to the People's Republic of China occupation disease prevention law "," People's Republic of China radiation pollution prevention and control law ", the basic standard GB18871-2002< ionizing radiation protection and safety of radiation sources", the public emergency GB/T17982-2000< under nuclear accident by laws and regulations and the health standard dose estimation model and parameter > etc. the iron and steel enterprises, develop radiation safety management system, establish contingency plans for iron and steel enterprises the risk of radiation accidents.
Result
As of December 31, 2009 1., the Department of Hubei and Wuhan Steel Company has a total of 332 radioactive sources, Aoyama headquarters business units in a total use of X ray apparatus and medical accelerator 119. All radioactive sources, radioactive activity ranges from 0.0925GBq to 1.85TGBq, the total 12.289TBq. radionuclide activity category mainly for 60Co, 241Am, 241Am-Be, 85Kr, 137Cs which, 3H-Ti; in 185 of radioactive sources, the total activity of 10.394TBq largest source for the 1.85TBq, the minimum source 0.0925GBq; inventory of radioactive sources 147, the total activity of 1.895TBq, the largest source of 0.185TBq, the minimum source 0.185GBq. all to IV and V source, the total radiation source 91.27%.
2. environmental dose level monitoring, source surface 5cm X- gamma air absorbed dose rate is 0.06-11.81 mu Sv/h; 100cm total air absorbed dose rate in the range of 0.03-66.78 ~ Sv/h, source and sink of surrounding air absorbed dose rate range: 0.11-0.14 ~ Sv/h, an average of 0.124 Sv/h, were lower than the national standard limit dose.
3. of the 80 workers for personal dose monitoring effective radiation dose in the range of 0.568mSv-6.130mSv years, the average annual effective dose for 1.893mSv.87.5% staff annual effective dose was below 2mSv, the staff of 80% people annually at a dose of 1mSv following.1.25% years were higher than that of 5mSv. group dose dose was 151.410man / mSv, the silicon steel factory. Cold rolling mill, the gold company, quality inspection center, research institute annual dose were 3.032mSv, 1.460mSv, 2.438mSv, 1.285mSv, 1.757mSv (average 1.893mSv).
4. since 1980s, the Department of Hubei and Wuhan steel had occurred 4 stolen radioactive sources, control events, 7 scrap incoming radiation dose exceed the standard phenomenon. 7 radioactive accidents occurred in the past 10 years, the level of all accident radiation accidents. The use of GM (1,1) obtained by fitting the data of accident prediction the model, by Ck=0.2059 test, Pk=1.1000 model has higher precision. The accident forecast for the year 2011, according to the prediction results for 0.94., if you do not take effective preventive measures, the 2011 workshop accident will be 0.94.
Identification of radiation risk events were 5. WISCO using the risk assessment matrix method, which can be divided into three categories: radioactive sources and radioactive substances related accidents, radiation risk events caused by production practice, radiation workers and the public. The crowd accident exposure accident lost / stolen radioactive sources, radioactive material transport exceed the standard. Scrap radioactive contamination of three risk factors risk level is E-76 (high risk), occupation of radiation workers was H-56 (high risk).
conclusion
1., the radiation dose level of the radiation sources of WISCO is lower than the national dose limit. However, there are many kinds of problems, such as complex species, high frequency of use, and potential safety hazards.
2., the radiation dose level of each source unit and the personal annual dose of radiation workers are lower than the national dose limit (20mSv/), and the annual effective dose level and the collective dose level of silicon steel plant are the highest.
3. GM (1,1) model predicts that if more effective preventive measures are not taken, there may still be 0.94 incidents in Wuhan Iron and steel company in 2011.
4. iron and steel enterprises radiation risk factors, risk control is difficult. To develop targeted radiation risk prevention and control measures, including: perfecting the management organization, perfecting rules and regulations, strengthen radiation protection, strengthening operation management, popularization of protection consciousness and the health management of radiation workers, the mechanism of accident disposal system and scientific periodical inspection and supervision, to ensure the safe production of enterprises is very necessary.

【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R144

【参考文献】