Estimation Of Unknown Activities By Comparative Calibration Method

Among the stored radioactive wastes in the Atomic Energy Authority Radwaste Waste Storage Facilities, several sources were identified as unknown. These sources were brought to the storage facility 1 yr ago. Gamma-Ray spectroscopic radioassays of these sources showed two main gamma-energy lines of 1.17 and 1.33 MeV, which are the main characteristic feature of Co-60 radionuclides. Estimation of their activities were carried out using a simple intercomparison technique with a Co-60 reference source of activity 146 MBq (3.95 mCi). The sources activities were found to be in the range 2.70-3.50 GBq (73 to 95 mCi). The authors beneficially found and planned for future use of these sources in research, routine radiation protection programs as well as in calibration.