Analysis of the use of the IAEA rapid method of ⁸⁹Sr and ⁹⁰Sr in milk for environmental monitoring

Rapid methods that are used during nuclear accidents or incident situations must first be implemented and validated in radioactivity measurement laboratories, so they can be ready to provide quick answers to governments, regulatory organizations and people in such situations. As these accident situations are rare and the methods are thus not frequently used, the best way to achieve this is to use the same methods for both routine environmental monitoring and rapid or emergency situations. Before this can be done, however, an analysis of the conditions under which a rapid method could be effectively used in routine situations should be carried out. This work analyses the performance of the rapid method for the simultaneous determination of ⁸⁹Sr and ⁹⁰Sr in milk, published by the IAEA, and compares it with another, more conventional method used for routine environmental purposes. Through numerical calculations and considering different ⁸⁹Sr and ⁹⁰Sr activities, we also conducted a study to obtain the optimum values for determination parameters – such as sample mass, counting times, time lapse between measurements and background counting times – that will allow the use of the IAEA rapid method as a routine environmental one. - Highlights: • Numerical analysis of an IAEA rapid method of ⁸⁹Sr and ⁹⁰Sr in milk for environmental purposes. • Compared with a method used in environmental monitoring. • Detection limits obtained are compared with requirements from different regulations. • Large counting times and time lapse between Cherenkov and liquid scintillation counting are needed to achieve that purpose.