Actinides AMS Sample Processing Capability at ANSTO – A tour by poster
Mr David Child1, Dr M.A.C. Hotchkis1
1ANSTO, Lucas Heights, Australia
Designing and developing sample processing facilities for processing of samples for actinides analysis poses some unique challenges. Facilities for actinide research need to be tailored to specific application areas, sample composition for each area of research may contain isotopic ratio mixtures and isotopic concentrations incompatible with the sensitivity requirements and background/blank levels of adjacent projects. This is due to the widely varying sample compositions related to the source of the actinides, for example age dating of nuclear materials compared to safeguards analysis of uncontaminated swipe samples.
The Actinides AMS capability at ANSTO’s Centre for Accelerator Science is operated by a small research group focussed on providing support for government, academic and industry users, and stakeholder projects. These facilities have been designed with versatility in mind, specialising on provision of high sensitivity analyses for low activity samples and projects to support the greatest breadth of applications.
The current range of research applications supported include:
Environmental occurrence and distribution of anthropogenic actinides
– Actinides bomb pulse dating and tracing – geomorphology
– Radioecology – biological uptake of nuclear activities environmental release
Non-proliferation and monitoring
– Nuclear Safeguards – swipe sample monitoring and wide area environmental sampling
– Nuclear Forensics – nuclear material characterisation and dating
– Environmental monitoring – emergency response, contamination monitoring, baseline studies
Actinides from astrophysical events
The Actinides AMS chemistry laboratory has been purpose built for low level environmental actinides sample preparation, in particular for high sensitivity low abundance actinides isotope (²³³U, ²³⁶U, ²³⁹Pu, ²⁴⁰Pu, ²⁴¹Pu, ²⁴⁴Pu), allowing for segregation of “dirty” operations (unpacking and handling of dried environmental materials) to progressively cleaner environments whilst still allowing for aggressive sample destruction and dissolution. To achieve this a range of specialised sample preparation components and configurations have been employed to allow for a wide range of sample types (swipes/filters, soils/sediments, biota, water, minerals) with elimination of possibility of sample crosstalk, dust and external atmospheric ingress and contamination. This is especially important given the potential for high dynamic ranges of isotopic concentrations between consecutively handled research projects.
To support research applications unable to be handled in the AMS Actinides laboratory, partnered facilities with capability to process active materials are utilised to pre-treat samples and deliver subsamples suitable for handling in the low-level AMS laboratories.
We present here the methodologies, processes and backgrounds achieved to deliver high sensitivity actinide samples for a range of applications and give the current status of the Actinides AMS capability.
David Child has worked within the accelerator group at ANSTO for over 20 years as a chemist and sample preparation expert, supporting projects across nuclear safeguards and forensics, actinides bomb pulse dating for geosciences, cosmogenic dating and radiocarbon dating.