Objective To ensure the effectiveness and improve the capacity of laboratories in the measurement of γ spectra of radionuclides. Methods A statistical analysis was performed using relative deviation, accuracy, precision, and relative combined uncertainty for the nationwide assessment of radionuclide γ spectrum measurement. Results In the assessment from 2018 to 2020, our laboratory showed qualified or above results, and the performance in 2019 was excellent. The maximum relative deviation of 11 measurements from 2018 to 2020 was 18.01%. The assessment showed |Z_test|≤1 and U_test≤2.58 in 2018, |Z_test|≤1 and U_test≤1 in 2019, and U_test≤1 and U_rel≤20% in 2020. Conclusion Our laboratory employs the correct method for radionuclide γ spectrum measurement, and the analysis data are accurate and reliable.

Objective To establishment a process of monitoring waste resin clearance in nuclear power plants, and to meet clearance requirements and simplify the monitoring work. Methods In accordance with the requirements specified in current laws, regulations, and standards in China, as well as the practice of slightly polluted waste resins generated during the operation of nuclear power plants, in-depth discussion was conducted on sampling methods, sample uniformity and representativeness tests, radiation monitoring contents and methods, and simplified monitoring processes, in order to accurately monitor the radionuclide activity of waste resins to be cleared. Results A process was established to monitor waste resin clearance in nuclear power plants. A total of 55 barrels of waste resins were cleared and the radiation levels met the requirements. Conclusion An effective clearance process can facilitate the sampling of representative resins, improve the accuracy of monitoring data, differentiate radioactive waste from cleared waste, and simplify the monitoring process. Our results provide a basis and reference for future waste resin clearance.

Objective To improve the analysis of ¹³⁴Cs, ¹³⁷Cs, and ⁶⁰Co in aerosol samples by the national key radiation environment laboratories. Methods Intercomparison of analysis results of ¹³⁴Cs, ¹³⁷Cs, and ⁶⁰Co in standard aerosol samples was performed among the national key radiation environment laboratories according to Gamma spectrometry method of analyzing radionuclides in biological samples (GB/T 16145-1995 ), and the intercomparison results were evaluated by the standard deviation. Results Six laboratories were involved in the intercomparison. For ¹³⁴Cs, 50% of the laboratories showed a relative deviation less than 10%, and 50% showed a relative deviation of 10%-20%. For ¹³⁷Cs, 33.3% of the laboratories showed a relative deviation less than 10%, and 76.7% showed a relative deviation of 10%-20%. For ⁶⁰Cs, all laboratories showed a relative deviation less than 10%. The overall intercomparison results were acceptable. Conclusion The laboratories in this intercomparison show generally good results.