Particle Standard - JRC releases the first uranium oxide (U3O8) micro-particle reference material for nuclear safeguards and security

For verifying the absence of undeclared nuclear material and activities, measurements of uranium isotope ratios in particles containing uranium collected by national and international safeguards authorities in environmental samples at nuclear facilities during inspections are performed.

Nuclear security authorities also use environmental samples for evidence collection in cases of seizures of nuclear material. Networks of analytical laboratories subjected to a rigorous quality management system perform these analyses. Certified reference materials and quality control samples at the particle level are needed.

The European Commission Joint Research Centre (JRC) – in collaboration with the Forschungszentrum Jülich (FZJ, Juelich/Germany) and the International Atomic Energy Agency-Safeguards Analytical Service (IAEA-SGAS, Seibersdorf/Austria) has produced IRMM-2329P, the first uranium oxide (U3O8) micro-particle reference material certified for major and minor uranium isotope ratios and uranium mass per particle.

At the FZJ a vibrating orifice aerosol generator (VOAG) was employed for producing micro-meter-sized uranium oxide particles from a certified uranium nitrate base solution certified at JRC. IAEA-SGAS confirmed the certified isotope ratios on the particles themselves.

The preparation and certification of the IRMM-2329P reference material are described in detail in the certification report: Preparation and Certification of the Uranium Oxide Microparticles IRMM-2329P

IRMM-2329P was tested, before being released, for conformity assessment of safeguards laboratories and laboratories in the field through the NUSIMEP-9 (Nuclear Signatures Inter-laboratory Measurement Evaluation Programme) interlaboratory comparison on “Uranium isotope amount ratios and uranium mass in uranium micro-particles”. The JRC Science for policy report is available online:

NUSIMEP-9: Uranium isotope amount ratios and uranium mass in uranium micro-particles

IRMM-2329P reference material can be ordered from the online Joint Research Centre Certified reference materials catalogue