A way to limit the corrosion in the Molten Salt Reactor concept: the salt redox potential control

Mathieu Gibilaro (1) , Laurent Massot (1) , Pierre Chamelot (1)

1 LGC - Laboratoire de Génie Chimique

The possibility of controlling the salt redox potential thanks to a redox buffer in the Molten Salt Fast Reactor was investigated, the goal was to limit the oxidation of the reactor structural material. Tests were performed in LiF-CaF2 at 850 °C on two different redox couples to fix the salt potential, Eu(III)/Eu(II) and U(IV)/U(III), where the first one was used as inactive system to validate the methodology to be applied on the uranium system. A metallic reducing agent (Gd plate for Eu, and U plate for U system) was inserted in the salt, leading to a spontaneous reaction: Eu(III) and U(IV) were then reduced. Eu(III) was fully converted into Eu(II) with metallic Gd, validating the approach. On the U system, the U(IV)/U(III) ratio has to be set between 10 and 100 to limit the core material oxidation: addition of metallic U decreased the concentration ratio from the infinite to 1, showing the feasibility of the salt redox potential control with the U system.

Mots clés: Redox potential control; Molten Salt Fast Reactor; U

Domaines: Génie chimique; Génie des procédés

Mathieu Gibilaro, Laurent Massot, Pierre Chamelot. A way to limit the corrosion in the Molten Salt Reactor concept: the salt redox potential control. Electrochimica Acta, 2015, 160, pp.209-213. ⟨10.1016/j.electacta.2015.01.142⟩. ⟨hal-01905762⟩