AMS for nuclear safeguards and forensics 

Key contact:
Mike Hotchkis
ANSTO Institute for Environmental Research
PMB 1, Menai NSW 2234, Australia
Phone: +61 2 9717 3148
Email: Michael.hotchkis@ansto.gov.au

 
ANSTO has developed ultra-sensitive isotopic tracing techniques for detection of nuclear signatures.

Human activities involving nuclear materials, such as handling uranium and plutonium, leave tiny but detectable traces in the neighbouring environment. From these traces, the nature of the activities, whether legal or illegal, can be determined.

The International Atomic Energy Agency (IAEA) uses environmental sampling as part of its strategy for monitoring compliance with the Nuclear Non-proliferation Treaty.  The IAEA enlists the help of a number of laboratories from around the world, including ANSTO, to analyse these samples.

The same sampling and analytical techniques are applied by other agencies, for example those responsible for detection of illicit trafficking of nuclear and radioactive materials.

ANSTO's role

ANSTO participated in early field trials and studies of analytical capabilities, in particular the use of the long-lived fission product 129I, which can be detected at extremely low levels by Accelerator Mass Spectrometry (AMS). With the assistance and support of the Australian Safeguards and Non-proliferation Office (ASNO), ANSTO had by 1999 developed AMS analysis of actinides, focussing on the rare isotope 236U, which is a sensitive indicator of irradiated uranium. More recently, we have extended our analytical capabilities to include the full range of long-lived uranium and plutonium isotopes.

ANSTO qualified as a member of the IAEA's Network of Analytical Laboratories (NWAL) in 2002, on the basis of its AMS analytical capabilities.

Details of analytical capabilities using AMS

Sample materials analysed: Cotton or other swipes; aerosol filter materials; environmental materials including soil, sediment, water, biota.

Measurement technique: Accelerator Mass Spectrometry. AMS provides measurements of isotopic ratios. Measurements of concentrations are derived from isotope dilution by adding known quantities of spikes.

Analytes

 
 Note: A number of other actinide radioisotopes can be measured if required.

Analytical precision: Isotopic ratios are measured with a precision of around five per cent. For isotopes occurring at very low levels, eg 236U and Pu isotopes, the precision may be limited by counting statistics.