The reactivity risk in fast reactors and the related international experimental programmes CABRI and SCARABEE

CABRI and SCARABEE are two experimental reactors, located at Cadarache, France. During the last twenty years, they were operated by IPSN, together with other French and foreign research institutes, in order to conduct several experimental programmes to study the problems raised by the reactivity risk in fast reactors. Transient over-power tests were realized in CABRI, whereas in SCARABEE bundles with up to 37 pins were brought to melting and even boiling. The results led to code developments and general engineering expertise, and helped to give a better understanding and prediction capability of different hypothetical accident scenarios, like core disruptions and subassembly blockages. A new programme is underway to complement some important issues, mainly linked to other scenarios, like an accidental control rod withdrawal and the risk of recriticality of a molten core. (C) 1997 Published by Elsevier Science Ltd.