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News article26 April 2022Joint Research Centre

JRC releases IRMM-3000a, the diluted version of the IRMM-3000 highly enriched uranium (HEU) reference material series

The new IRMM-3000a series is a diluted version of the IRMM-3000 series certified in 2021, a set of highly enriched uranium material standards needed for calibrating mass spectrometry measurements of nuclear samples for nuclear safeguards and security

Ampoule of IRMM-3020a, the new reference material with a 20 % enrichment of 235U
Ampoule of IRMM-3020a, the new reference material with a 20 % enrichment of 235U
EU, 2022

Why is important

The reduced uncertainties of the 235U enrichment for the IRMM-3000 and IRMM-3000a series reference materials allow a significant improvement of precision and accuracy for the analysis of highly enriched nuclear material. This type of reference material is needed by nuclear safeguards authorities to monitor the use and prevent the proliferation of highly enriched uranium material, commonly used in enrichment facilities, nuclear weapons facilities and for the production of medical isotopes, for example 99Mo for 99mTc generators. In addition, the diluted IRMM‑3000a series includes enough uranium for high sensitivity mass spectrometers calibration, such as multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) and is therefore also suitable for use in scientific areas such as geochemistry and cosmochemistry.

JRC Contribution

By offering the diluted IRMM-3000a series, JRC makes this valuable series of reference materials available to an extended user community.

Unique preparation

Like the IRMM-3000 series, the IRMM-3000a series of uranium nitrate solution reference materials includes five materials with different isotopic compositions, covering a range from 20 % to 90 % for the enrichment of 235U. The relative uncertainties of the isotope ratios 235U/238U and the 235U enrichment have an unprecedented level of 0.02 % (95 % confidence level), due to the gravimetrical preparation.

Image of Uranium oxides (235U and 238U)
Uranium oxides (235U and 238U) after the calcination performed for the formation of the stoichiometric U3O8 oxide form, prior to the gravimetrical mixing of the original IRMM-3000 series.
EU, 2022

More information

The preparation and certification of the IRMM-3000a and IRMM-3000 series of reference materials are described in the JRC certification report: Preparation and Certification of Highly Enriched Uranium Nitrate Solutions, IRMM-3000 Series

The IRMM-3000a series can be ordered from the certified reference materials online catalogue of the European Commission's Joint Research Centre (JRC).



Publication date
26 April 2022
Joint Research Centre