2018年参加全国放射性核素γ能谱分析比对结果

Results of participating in the national intercomparison of radionuclideanalysis by γ spectroscopy in 2018

目的验证本实验室所用的γ能谱测量系统,确认γ放射性核素测量分析方法和技术的可靠性。方法通过参加2018年中国疾病预防控制中心辐射防护与核安全医学所组织的全国放射性核素γ能谱质量控制分析比对,分别用相对比较法和效率曲线法分析土壤样品中核素232 Th、40K、137 Cs的活度浓度。结果相对比较法测得的3种核素的活度浓度与参考值的偏差为0%~14.1%,U检验值为0.15~2.35;效率曲线法测得的3种核素的活度浓度相对参考值的偏差为2.8%~18.5%,U检验值为0.42~2.58,均在合格范围内。结论本实验室所用的γ能谱测量系统性能稳定,分析方法可靠,但测量结果与参考值的相对偏差较大,实验室质量控制技术有待进一步完善。

Objective To verify theγspectroscopy system used in our laboratory,and confirm the reliability ofanalysis method and technology.Methods By participating in the national intercomparison of radionuclide analysis organized by National Institute for Radiological Protection,China CDC,232Th,40K and 137Cs contents in the soil samplewereanalyzedwith both the relative and efficiency curve methods.Results Compared with the reference activity concentrations,the ranges ofrelative deviations for the three nuclides were 0%~14.1%and 2.8%~18.5%and the ranges of U test valueswere0.15~2.35 and 0.42~2.58,by using the relative method and the efficiency curve method,respectively,.The results were all in the qualified range.Conclusion Theγspectrocopy system in our laboratory isstable,and theanalysis methodsarereliable.Further quality control techniques are still needed to improve the measurement accuracy.