Environmental monitoring in support of international nuclear safeguards and test ban agreements

Long-lived radioisotopes introduced into the environment by tests of nuclear weapons and by the operation of nuclear fuel reprocessing plants can be analysed with ultra-high sensitivity by accelerator mass spectrometry (AMS). Isotopic concentrations of 106 atoms per gram and isotopic ratios of 1 part in 1015 can be detected in milligram samples taken from selected environmental media. ANSTO is setting up specialised beamlines at the ANTARES AMS system for the ultrasensitive analysis of long-lived radioisotopes, such as 129I, produced by nuclear activities and for the direct detection of uranium, plutonium and other actinides. It is believed that these new analytical methods will be valuable in the verification of compliance with the terms of international safeguards and nuclear test ban treaties