This study shows that, by applying this CADOR approach to a Generation-IV oxide-fuelled SFR, the resulting core can be made inherently resistant to reactivity insertion accidents, while also having increased resistance to loss-of-coolant accidents. | CADOR Core with Adding DOppleR effect concept application to sodium fast reactors EPJ Nuclear Sci. Technol. 5 1 2019 Nuclear Sciences A. Zaetta et al. published by EDP Sciences 2019 amp Technologies https epjn 2018049 Available online at https REGULAR ARTICLE CADOR Core with Adding DOppleR effect concept application to sodium fast reactors Alain Zaetta1 Bruno Fontaine1 Pierre Sciora1 Romain Lavastre1 Robert Jacqmin1 Vincent Pascal1 Michel Pelletier1 Gérard Mignot1 and Aurélien Jankowiak2 1 CEA Nuclear Energy Division Cadarache Center 13108 Saint-Paul-lès-Durance France 2 CEA Nuclear Energy Division Saclay Center 91191 Gif sur Yvette France Received 5 October 2017 Received in final form 9 October 2017 Accepted 30 November 2018 Abstract. Generation-IV sodium fast reactors SFR will only become acceptable and accepted if they can safely prevent or accommodate reactivity insertion accidents that could lead to the release of large quantities of mechanical energy in excess of the reactor containment s capacity. The CADOR approach based on reinforced Doppler reactivity feedback is shown to be an attractive means of effectively preventing such reactivity insertion accidents. The accrued Doppler feedback is achieved by combining two effects i introducing a neutron moderator material in the core so as to soften the neutron spectrum and ii lowering the fuel temperature in nominal conditions so as to increase the margin to fuel melting. This study shows that by applying this CADOR approach to a Generation-IV oxide-fuelled SFR the resulting core can be made inherently resistant to reactivity insertion accidents while also having increased resistance to loss-of-coolant accidents. These preliminary results have to be confirmed and completed to meet multiple safety objectives. In particular some margin gains have to be found to guarantee against the risk of sodium boiling during unprotected loss of supply power accidents. The main drawback of the CADOR
