Sensitivity enhancement in gamma-spectrometric determination of impurity europium radionuclides in production of Gd-153

The standard procedure of processing gamma-spectra with calculation of the areas of separate photopeaks does not meet the requirements to the detectio n limit, accuracy, and time of determination of Eu-152,Eu- 154,Eu- 156 in a mounts corresponding to their activity ratio to Gd-153 less than 7.0 x 10(- 4)% and to Tb-160 less than 5%. A new procedure is proposed for treating ga mma-spectra with determination of Eu-156 from the sum of detected counts in the 1610-2300 keV band, followed by calculation of the content of the othe r Eu isotopes from that of Eu-156. The method was tested on real samples. F or samples of process solution purified to remove Eu, this method is more s ensitive than the standard procedure by a factor of approximately 10. It ca n be used both in monitoring of Gd-153 production and in its certification.