Year
2023
File Attachment
Abstract
The International Atomic Energy Agency (IAEA) and its worldwide Network of qualified
Analytical Laboratories (NWAL) conduct analytical measurements on swipe samples taken
during inspections at nuclear facilities to verify the absence of undeclared nuclear materials and
activities. These efforts, together with the increasing number of samples (more than 450 per
year) to be analysed require constant quality control, further advancement of highly sensitive
analytical methods incl. the development and provision of tailor-made reference materials as
well as the permanent build-up of new NWAL capabilities.
In 2020 the safeguards laboratories at Forschungszentrum Jülich GmbH (FZJ) were qualified
as the first member for the provision of microparticulate reference materials. These reference
particles are applied to strengthen the IAEA’s quality control system for particle analyses
including analytical instrument calibration, method development and validation as well as their
application in interlaboratory exercises.
This paper will provide an impression of the several steps required towards the provision of the
microparticulate reference materials. Exemplarily, these steps will be discussed on our recent
campaign to the IAEA on the production of the first highly enriched uranium-oxide reference
microparticles. They include (1) the discussion and agreement on the specification of the
individual particles, e.g. composition and particle size, but also the number and nature of
samples, (2) the preparation of the laboratories considering the internal Standard Operation
Procedures (SOPs) for the safeguards laboratories at FZJ, (3) the certification of starting
solutions at Joint Research Centre in Geel, such as the IRMM-3050 isotopic reference material
and (4) the production of the particles at FZJ. A specific discussion will focus on (5) the required
analyses, that includes the process control measurements as well as the verification
measurements via advanced mass spectrometric methods (MC-ICP-MS and LG-SIMS)
conducted at FZJ, Oak Ridge National Laboratory (ORNL) and Heidelberg University,
respectively.