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News article26 September 20181 min read

Standards for Standards - JRC releases the new uranium reference material series IRMM-2019-2029 for nuclear safeguards measurements

screw-cap ampoules used during the processing of the IRMM-2019-2029 series
Screw-cap ampoules used during the processing of the IRMM-2019-2029 series
© EU, 2019

The new IRMM-2019-2029 series of reference materials is designed to serve as the ideal set of "Material Standards" needed for calibrating Thermal Ionization Mass Spectrometry (TIMS) measurements of nuclear safeguards samples, in particular for the application of the so-called "Modified Total Evaporation (MTE)" and "Double Spike Method (DS)" methods, as described in the respective "Documentary Standards" ASTM C1832 and ASTM C1871a.

The IRMM-2019-2029 series of uranium nitrate solution reference materials includes eleven uranium reference materials with different isotopic compositions, covering the range from depleted to low enriched uranium. The certification of the isotopic composition was performed by taking advantage of the newly established and standardized measurement procedures "MTE", ASTM C1832 and "DS", ASTM C1871a, using a new set of calibrants, gravimetrically prepared by mixing of highly enriched 233U, 235U, 236U and 238U oxides or solutions. This strategy has led to an unprecedented level of small uncertainties on the certified values, in particular for the so-called minor isotope ratios 234U/238U and 236U/238U. This is important for characterizing nuclear material and for verifying users' declarations by nuclear safeguards authorities.

The preparation and certification of the IRMM-2019-2029 series is described in detail in the certification report, available at

In addition, a peer reviewed scientific paper has been published online by the Journal of Radioanalytical and Nuclear Chemistry, which is available using this link:

The IRMM-2019-2029 series can be ordered from the online catalogue:

Mass Spectometer
Mass Spectometer
© EU, 2019


Publication date
26 September 2018