Nationwide intercomparison for radionuclide analyses through γ-spectrometry method in 2014

Objective: To improve the technical levels and analytical ability of γ-spectrometry analysts for agencies engaged in radiation measurement and assessment and to promote further advances of monitoring methods for γ-spectrometry analysis laboratories in our nation. Methods: A nationwide intercomparison on γ-spectrometry measurement for activity concentration of ⁴⁰K, ¹³⁷Cs, ²⁰⁸Tl, and ²²⁸Ac in soil was organized in 2014. Results: Thirty-one laboratories have participated in this intercomparison. Among these laboratories, 26 laboratories showed 'acceptable' results, which include 2 laboratories with 'excellent' status, while 5 laboratories showed 'unacceptable' results. The production percentages of 'acceptable' results and 'excellent' status are 84%(24/31) and 6%(2/31), respectively. Conclusions: The measurement values reported by most of the laboratories involved in this intercomparison showed a good agreement with the reference values. Therefore, these values may provide a reliable measurement result during measurement in γ-spectrometry analyses. However, proper operation of γ-spectrometers and its regular calibration must be further emphasized to obtain accurate measurements to improve the calculation of nuclear data in some laboratories. (authors)