Unattended Measurement Station (UMS): Towards the complete Characterisation of fresh LEU Assemblies

The Joint Research Centre of the European Commission, in collaboration with EURATOM Safeguards, developed an unattended measurement station (UMS) for characterising fresh LEU fuel assemblies. The UMS provides a neutron measurement based on the active neutron coincidence counting technique using an AmLi interrogation source (neutron collar). The system was installed at FBFC-Framatome ANP fabrication plant at Romans-sur-Isère, France, where the assemblies will be verified for gross and/or partial defects. The facility operator places each fuel assembly in the measurement station in the absence of the inspector. The assembly identification number, normally located in the element head, is read by a 2D/3D Laser scanning system integrated into the measurement station. The identification incorporates optical character recognition (OCR) technology to interpret the 2D/3D image. For reviewing purposes, each 2D/3D acquired image is locally archived. The UMS provides unattended service for 100 days without inspector intervention. The only intervention required is the insertion and removal of the fuel assemblies by the facility operator, using the facility’s on-site heavy-duty crane. All measurement and identification activities are pre-programmed. This includes the loading and unloading of the AmLi source. Inspectors program the UMS to characterise a fuel element at different heights and/or make a full scan measurement of the whole assembly. All results are archived in a protected database to be reviewed during next inspector’s visit. The permanent installation of the UMS at FBFC France represents the successful implementation of a new Safeguards verification device characterized by: a) unattended measurement and monitoring devices; b) dual-use equipment. The paper illustrates the experience of developing and installing an unattended integrated Safeguards system. It shows the verification process, discusses the first experience after permanent installation of the instrument and reflects on training needs for inspectors and operators.