Improvements in Precision and Accuracy of Uranium Isotope Ratio Measurements for Reference Materials Certification at IRMM

For the certification of nuclear isotopic reference materials a new state-of-the-art thermal-ionisation mass-spectrometer (TIMS), the Thermo Electron “Triton”, was installed at IRMM in January 2004. Significant progress has been made particularly for measurements of the 234U/238U and 236U/238U (the so-called “minor”) isotope ratios. Using new measurement procedures for the Triton mass spectrometer, more precise and accurate isotopic data for the minor isotopic ratios have been obtained for a number of old and new reference materials, thus allowing a (re-) certification of their isotopic composition. This includes the well known IRMM-183-187 series and also the REIMEP 15 campaign samples. During the re-certification of the REIMEP 15 samples, the observed deviation between the participant results and the previously certified ratios by IRMM in certain cases has been overcome.

ALONSO MUNOZ Adolfo;  KUEHN Heinz;  VERBRUGGEN Andre;  WELLUM Roger;  TAYLOR Philip; 

RICHTER Stephan; 

2006-11-09

EC JRC Ispra (ESARDA)

JRC34135