如何正确理解和使用辐射屏蔽防护设计中的U、T因子

How to correctly understand and use U and T factors for radiation shielding design

目的 了解我国职业卫生监督和服务机构的有关人员对辐射屏蔽防护设计中利用因子（U）、驻留因子（T）理解的现状，分析存在的主要问题，提出改进建议。方法选择建设项目辐射屏蔽防护设计中的一个典型案例，对相关人员的认知水平以笔试形式考核，收集考卷，进行分类统计、分析。结果通过对87份有效考卷的分析，U、T因子使用过程中存在的主要问题是对辐射源项与职业病危害因素的关系区分不清、场所危害和接触危害的概念理解不贴切等。结论应加强对有关法律、法规和技术标准，特别是《电离辐射防护与辐射源安全基本标准》（GB18871—2002）的学习和领会，预防和控制放射性职业病危害的发生。

Objective To find out how the personnel employed in supervision and service agencies for occupational health correctly understand U and T factors for radiation shielding design, analyze the main existing problems, and put forward measures for improvement. Methods By means of selecting a typical case of structural shielding design and evaluation, 106 test papers were collected from concerned personnel, reviewed according to comprehension levels, and conducted by statistical analysis for 87 test papers. Results The results from statistical analysis show that many personnel cannot distinguish the factors resulting occupational disease hazard from the radiation sources, cannot correctly understand the concepts of field hazards and touching hazards, etc, when they use U and T factors. Conclusions In order to prevent and control the radiological occupational hazards, personnel employed in supervision and service agencies for occupational health should strengthen their comprehension of the law, legislations, and technical standards related, especially the basic standards for protection against ionizing radiation and for the safety of radiation sources （GB 18871-2002）.