Standardization of Pr-142 activity concentration

Pr-142 (praseodymium-142), a potential radionuclide for brachytherapy, was produced after irradiating high purity natural Pr2O3 powder in a research reactor. The irradiated powder was then dissolved in acids and diluted for measurement. Several radioactivity measurement methods were used in the standardization of Pr-142 radionuclide. This work reports the results of standardization of Pr-142 with CIEMAT/NIST efficiency tracing method, gamma spectrometry and a calibrated ionization chamber. The activity measured from different standardization methods are compatible with each other within the uncertainty limits. The CIEMAT/NIST efficiency tracing method gives the lowest uncertainty and is a reliable method for the standardization of this radionuclide.