AMS measurement of environmental U-236 preliminary results and perspectives

U-236 is a 23.4 Ma half-life radioactive isotope whose natural global abundance is expected to be overwhelmed in many places by its production and release during nuclear power generation. The detection of excess U-236 in the environment is therefore a method of monitoring the presence of activated uranium. However, U-236 has not been widely used for environmental studies due to the difficulties of measuring it at low levels with standard cu-spectrometry or thermal ionization mass spectrometry. In principle, accelerator mass spectrometry can overcome some of the difficulties encountered in the traditional methods, making it possible to detect U-236 at very low levels so that a large range of environmental samples can be analyzed. In this paper, we report some preliminary results of the U-236 measurements of four water samples from the US Idaho Chemical Processing Plant. Limitations with our current AMS system and the perspectives for considerable improvements will be discussed.