AMS for nuclear safeguards and forensics

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

	U isotopes	Pu isotopes	1291
Isotopes	233, 234, 235, 236, 238	239, 240	129, 127
Minimum detection limit	5fg for 236U 1ng total U	1fg	5x10-14 for the 129: 127 isotopic ratio

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.

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

Publications

A list of current publications can be found here: