Establishment of Independent Air Kerma Traceability for 60-Co at Radiation Protection Levels at CIEMAT

This paper describes the methodology implemented at the CIEMAT Ionizing Radiation Metrology Laboratory to establish independent air kerma traceability for 60Co radiation protection levels, based on the reference provided by the 137Cs primary standard. A secondary standard ionization chamber with an appropriate energy response was characterized, and its beam quality correction factor, , was determined via Monte Carlo simulations using the EGSnrc code. The results were validated through a comparison with long-term historical calibration data and further confirmed by CIEMAT’s participation in the EURAMET.RI(I)-S19 supplementary comparison, recently published in the BIPM KCDB. The excellent agreement with international reference values demonstrates the robustness of the developed method and the successful implementation of the new traceability chain.