210Pb determination in lead shields for low-level γ-spectrometry applying two independent radiometric techniques

210Pb radioimpurities in different lead pieces used for shielding low-level gamma-ray spectrometers have been determined through the application of two independent radiometric techniques: alpha-particle spectrometry (210Po) and Cherenkov counting (210Bi). Associated to each technique, simple radiochemical procedures have been developed for the isolation of the radionuclides of interest and/or their adaption to the measurement conditions. These determinations are very useful in designing low-level gamma-spectrometric systems as well as in the interpretation, evaluation and even simulation of their background spectra.