Use of Reference Materials for Destructive Analysis at the Institute for Transuranium Elements

In order to verify declared nuclear activities for safeguards purposes, high-performance analyses are a key element. The Joint Research Centre (JRC) of the European Commission runs for this purpose the Analytical Service at JRC-ITU, and on behalf of the Directorate General (DG) ENERGY (Euratom Safeguards) the two on site laboratories, at Sellafield, UK, and at La Hague, F. Destructive analyses provide highest accuracy and precision and therefore are part of the analytical techniques used. The isotopic composition and concentration of uranium and plutonium and analysis of impurities are performed using isotope dilution thermal ionisation mass spectrometry, titration, inductively coupled mass spectrometry; and carbon, nitrogen, and oxygen element content assay by fusion extraction. Reference materials play a crucial role to guarantee traceability, accuracy, and comparability of safeguard analyses. All three laboratories have different approaches in choosing the reference materials due to the local requirements. JRC-ITU produces internal reference materials complementary to certified reference material. The experience over the last 10 years is discussed with a focus on the set up of a technique for laser sealing of ampoules for long-term storage of liquid reference material.