New equipment for nuclear safeguards at Sellafield reprocessing plant
Under the Euratom Treaty, the European Commission has the duty to assure that nuclear material is not diverted from its declared uses. The aim of safeguards is to deter diversion of nuclear material from its declared (peaceful) use by maximising the chances of detection at an early stage. One of the methods to provide comprehensive control on the large flows of nuclear material through the reprocessing plants is the independent measurement of samples routinely taken at key measurement points.
In order to deal with the large number of samples taken, the safeguards authorities opted for the installation of individual laboratories at the sites of the reprocessing plants. On-site laboratories offer the Euratom safeguards inspectors independent analytical capacity of high quality and provide results within a short time.
After more than ten years of continuous operation, the European Commission - represented by the JRC and DG Energy - is renewing some of the oldest equipment. In this framework, a new mass spectrometer device has been installed in the on-site laboratory in Sellafield.
Mass spectrometry serves a twofold purpose at the on-site laboratories. Thermal Ionisation Mass Spectrometry (TIMS) is used to measure the uranium and plutonium isotopic compositions. Isotope Dilution Mass Spectrometry (IDMS) is employed to determine uranium and plutonium concentrations using a well-characterised reference material to spike the sample. The latter method is also used to characterise reference solutions produced in the on-site laboratories and needed to calibrate other analytical equipment.