某核设施安全关闭的辐射防护实践

目的 通过科学合理的辐射防护措施保障某核设施安全关闭工程中的辐射安全。方法 在该核设施安全关闭前期，对其放射性源项进行了辐射监测，根据监测结果对施工过程进行辐射风险分析，设计了安全关闭的施工流程，制定了科学合理的辐射防护方案并实施。结果 通过辐射监测结果可知，该核设施主要污染核素为¹³⁷Cs、⁹⁰Sr、²⁴¹Am，建筑物、设备及工器具等的放射性表面污染面积较大且污染严重，人员工作区域存在较高水平的γ辐射及放射性气溶胶；根据监测结果对工程的辐射风险进行了安全分析，采取了合理的施工流程和科学合理的辐射防护措施，确保了本工程的辐射安全。结论 本次辐射防护工作满足了本工程的辐射防护要求，为从事核设施退役相关工作的科研人员和管理部门提供参考。

Radiation protection during the safely shutdown of a nuclear facility

Objective To reach the goal of the safe shutdown of a certain nuclear facility by scientific and reasonable andr radiation protection measurements. Methods Before carrying out the safe shutdown work, the radioactive source term was investigated, radiation risk during the implement was analyzed according to the investigation result, the process of safe shutdown was designed, and proper radiation protection plan was formalized and implemented. Results According to the radiation survey of this facility, it was revealed that the major contaminated nuclides were ¹³⁷Cs, ⁹⁰Sr and ²⁴¹Am. The radioactive contamination area was relatively large and the contamination degree was severe. Besides, the gamma radiation and radioactive aerosol were relatively high in working area. The radiation risk of this program was analyzed according to the survey result. Proper work process was followed and good radiation protection was undertaken to ensure the radiation safety of this work. Conclusion The radiation protection work met the demand of this program, and provided reference for scientific researchers and management departments engaged in nuclear facility decommission work.