Improvements for spent fuel verifications by safeguards inspectors

Several European countries are preparing for the direct disposal of spent fuel. Most advanced are Finland and Sweden which target operations for the 2020s. In other EU countries, packaging of spent fuel in casks for interim storage is continuing at growing rates. Both situations present a considerable challenge to the safeguards authorities. This paper will describe a new method which allows the operator of an encapsulation plant to perform loading campaigns in absence of safeguards inspectors but with the assurance that spent fuel has been verified. Final storage projects in Sweden and Finland envisage conditioning in an encapsulation plant - the fuel will be encapsulated in copper canisters to be disposed in a final repository. Implementation of joint EURATOM and IAEA safeguards would target all assemblies to be verified. Inconsistencies will need to be communicated to the operator instantly to interrupt the loading process before a container is closed and moved to the repository. Consequently, the measurements and their evaluation need to be fully unattended and automated. This automation can now be implemented by a combination of ORNL's ORIGEN (Oak Ridge Isotope GENeration) code [1] and DG ENERs CRISP [2] (Central RADAR [3] Inspection Support Package). Under the US-DOE EURATOM cooperation Agreement concluded in 1995 [4], ORNL has packaged the ORIGEN software, part of the SCALE nuclear systems modelling and simulation package, for burn-up calculations in such a way that DG ENER could integrate the code as a spent fuel data analysis module in CRISP. DG ENER has developed the CRISP package which has been used for routine inspection use very successfully for several years. CRISP allows for automated review of large amounts of safeguards measurements. In combination with DG ENER's system for unattended Fork measurements, this approach will allow the design of a completely autonomous SF verification station. The system will be an integral part of a comprehensive IAEA/EURATOM safeguards verification scheme, will be linked to the safeguards HQs and shall indicate any inconsistencies to the operator autonomously. Before the operation of the encapsulation facilities, important parts of the system can be applied immediately to current spent fuel cask loading operations for intermediate storages.