参加环境放射性样品核素活度锗γ谱比对测量的总结

ACTIVITY COMPARISION MEASUREMENT OF RADIOACTIVE NUCLIDES IN ENVIRONMENT SAMPLES

本文介绍了我们参加的由中国计量科学研究院组织的“环境放射性样品的锗γ谱测量比对”工作的总结。用ＨｐＧｅγ谱仪，分别用效率曲线法和相对比较法测量了两个比对样品２￣＃和４￣＃中所要求测量的７个核素：￣（２３８）Ｕ、￣（２３５）Ｕ、￣（２２６）Ｒａ、￣（２３２）Ｔｈ、￣（４０）Ｋ、￣（６０）Ｃｏ和￣（１３７）Ｃｓ的活度。对多数核素用这两种方法所得结果在实验误差范围内相符。两种方法的平均值与参考值的偏离一般小于１０％，只有４￣＃样品所测到的￣（２３８）Ｕ和￣（２３５）Ｕ活度值与参考值的偏离分别为２５％和２１％。讨论了数据出现分岐的原因。

The intercomparison results of activities of radioactive nuclides in enviromentalsamples were described.This intercomparison was organized by National Institute ofMetrology(NIM).Using both the efficiency curve method and the relative comparisonmethod,the activities of ￣(238)U,￣(235)U,￣(226)Ra,￣(232)Th,￣(40)K,￣(60)Co and ￣(137)Cs were measured in twosamples 2￣# and 4￣# supplied by NIM.The results obtained with the two methods agreed witheach other within the range of experimental uncertainty for majority of the nuclides.The de-viations between our results and the reference values were less than 10%,except that the re-sults for ￣(238)U and ￣(235)U in sample 4￣# deviated from the reference values about 25%and 21%,respectively.The cause of data divergence was also discussed.