Development of a rapid procedure to analyse Pu, Am and ⁹⁰Sr in emergency urine bioassay in Ciemat bio-elimination laboratory: method validation by emergency bioassay intercomparison exercises

After a radiological or nuclear incident, it is necessary to give a prompt response and to know the number of persons exposed to internal contamination, to evaluate the contamination levels in each person and even and to identify the radionuclides involved. In vitro laboratories routine monitoring measurements employed to quantify ⁹⁰Sr and actinides in urine require radiochemical separation and long counting time, which implies a minimum of 1 or 2 weeks to obtain the results, respectively. In this work, rapid radiochemical separation method applied directly to urine samples is presented. It is based on minimal sample preparation, without co-precipitation phase, using extraction resin columns and vacuum box technology. Pu isotopes and ²⁴¹Am are isolated, electrodeposited and measured by alpha spectrometry, whereas ⁹⁰Sr is measured by liquid scintillation counting. Finally, results of the participation in European Radiation Dosimetry Group intercomparison on Emergency Bioassay exercise and Bundesamt fuer Strahlenschutz exercise validate the accuracy of this procedure. (authors)