IAEA Study on Passive Shutdown Systems for Fast Reactors: Status Review

Inherent and passive safety features are becoming very important for fast reactors especially when active systems such as the SCRAM-systems for reactor shutdown are not functioning properly. Passive shutdown systems can operate either continuously (analogous to reactivity feedback mechanism or function as a backup actuation method for the conventional reactor SCRAM system. Numerous passive shutdown systems designs have been developed over the years in fast reactor research programs across the world. To summarize the state-of-the-art in this field, the members of the technical working group on fast reactors at the IAEA (TWG-FR) has been collecting the various approaches, design principles, engineering solutions and their impact on reactor safety and operation, in a joint collaborative project over the last year. A review of a total of a large number of different systems, divided in to different categories depending on the way they are actuated, will be presented in a Nuclear Energy Series report written jointly by members of the TWG-FR group. Some of these systems and the general findings of the TWG-FR study group will be presented in the poster session at the FR17 meeting. (author)