Evaluation of different methods for measuring 89 Sr and 90 Sr: Measurement uncertainty for the different methods as a function of the activity ratio.

In case of a radiological emergency situation involving e.g. fission of uranium or plutonium, analysis of radioactive strontium will be of importance. The primary radionuclides of interest are 90 Sr, its progeny 90 Y and 89 Sr. A few days following an event, 89 Sr will be the predominant radioisotope of strontium. Most methods found in the literature are valid and applicable when measuring 90 Sr, but when samples contain both 89 Sr/90 Sr interference problematics arise. How these interferences are dealt with will have an effect on the uncertainty of the 90 Sr determination. This work aims at evaluating three measurement approaches, all mentioned in the literature, with respect to the measurement uncertainty when determining 90 Sr in an emergency preparedness situation and to propose a suitable measurement strategy.