1.Analysis of the results of the nationwide interlaboratory comparison of gross α and gross β radioactivity measurement
Yongyong CHEN ; Yanghai SHI ; Yuhua SHI ; Ping WANG ; Yuansheng LU
Chinese Journal of Radiological Health 2024;33(1):40-45
Objective To summarize and improve the related technical issues by analyzing the nationwide interlaboratory comparison of gross α and gross β radioactivity measurement over the years. Methods According to the requirements of interlaboratory comparison and the national standards, the gross α and gross β radioactivity in water were measured, and the results were analyzed to identify the influencing factors. Results From 2018 to 2022, our laboratory participated in five nationwide interlaboratory comparisons of gross α and gross β radioactivity measurement. The Z-test values for gross α and gross β measurement ranged from −0.24 to 1.8 and −1.4 to 0.35, respectively. The relative deviations ranged from −4% to 32% and −18% to 6%, respectively. All comparisons were within the acceptable ranges. Conclusion The analysis of comparisons showed that the results were within the acceptable ranges. The relative deviations between the measurement and the reference values have decreased over the years. The summary and improvement of related technologies have improved the measurement accuracy.
2.Analysis of the results from national interlaboratory comparisons of radionuclide analysis by γ spectrometry
Yanghai SHI ; Yongyong CHEN ; Yuhua SHI ; Yuansheng LU ; Dezhi HE ; Ping WANG
Chinese Journal of Radiological Health 2025;34(1):55-60
Objective To verify the accuracy of γ spectrometry by analyzing the results of national interlaboratory comparisons of radionuclide analysis by γ spectrometry from 2018 to 2023. Methods A statistical analysis was conducted on the results from multiple years of participation in the national interlaboratory comparisons of radionuclide analysis by γ spectrometry. The measurement results of radionuclide specific activities in soil were analyzed to provide technical support for improving the capability to analyze radionuclides in soil. Results The laboratory participated in six interlaboratory comparisons and conducted 23 radionuclide analyses by γ spectrometry from 2018 to 2023. The relative deviation was −12.20% to 8.11%, the |Ztest| was 0 to 0.61, the Utest was 0 to 0.62, and the Urel was 0.07 to 0.12. The overall pass rate was 100% and the excellent rate was 33.3%. In addition, 21 of the 23 (91.3%) radionuclide analyses showed full scores in experiment operation. However, the total scores were relatively low due to multiple oversights and lack of rigor in the preparation of the test reports, which prevented the laboratory from qualifying for the excellence evaluation process, resulting in a relatively low excellent rate. Conclusion The interlaboratory comparisons indicate that the measurements of radionuclides in this laboratory were all qualified, with full scores for experiment operation in several analyses. These results demonstrate that the soil radionuclide analysis system based on γ spectrometry is reliable and stable.