Safety-Related Optimization and Analyses of an Innovative Fast Reactor Concept

Sustainability

Barbara Vezzoni¹  Fabrizio Gabrielli²  Andrei Rineiski²  Marco Marchetti²  Xue-Nong Chen²  Michael Flad²  Werner Maschek²  Claudia Matzerath Boccaccini² 

[1] Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany;

关键词: fast reactors;    sodium void effect;    severe accident;    recriticality;   

DOI  :  10.3390/su4061274

来源: mdpi

【 摘 要 】

Since a fast reactor core with uranium-plutonium fuel is not in its most reactive configuration under operating conditions, redistribution of the core materials (fuel, steel, sodium) during a core disruptive accident (CDA) may lead to recriticalities and as a consequence to severe nuclear power excursions. The prevention, or at least the mitigation, of core disruption is therefore of the utmost importance. In the current paper, we analyze an innovative fast reactor concept developed within the CP-ESFR European project, focusing on the phenomena affecting the initiation and the transition phases of an unprotected loss of flow (ULOF) accident. Key phenomena for the initiation phase are coolant boiling onset and further voiding of the core that lead to a reactivity increase in the case of a positive void reactivity effect. Therefore, the first level of optimization involves the reduction, by design, of the positive void effect in order to avoid entering a severe accident. If the core disruption cannot be avoided, the accident enters into the transition phase, characterized by the progression of core melting and recriticalities due to fuel compaction. Dedicated features that enhance and guarantee a sufficient and timely fuel discharge are considered for the optimization of this phase.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.