Reactivity Assessment in Subcritical Systems

Sammanfattning: Accelerator-driven systems have been proposed for incineration of transuranic elements from spent nuclear fuel. For safe operation of such facilities, a robust method for reactivity monitoring is required. In this thesis, the most important existing reactivity determination methods have been evaluated experimentally in the subcritical YALINA-experiments in Belarus. It is concluded that the existing methods are sufficient for calibration purposes, but not for reactivity monitoring during regular operation of an accelerator-driven system. Conditions for successful utilization of the various methods are presented, based on the experimental experience.