Permanent staff : Sylvie DELPECH, Céline CANNES, Davide RODRIGUES

PhD students : Hugo SAUZET, Alexandre CHMAKOFF

Post-doctoral researcher : Victor HAQUIN

Description of the research activities

A molten salt chemistry laboratory was set up in Orsay in 2005 to study the concept of a fast-spectrum molten salt reactor (the Molten Salt Fast Reactor, MSFR) developed by the CNRS in the frame of the national program PACEN. Since then, experimental studies on the chemistry and treatment of liquid fuel (composed of a mixture of LiF, ThF4and UF4) have been carried out with national support but also through several European projects and an industrial collaboration with RHODIA (up to 2016), interested in a possible way of upgrading thorium. For two years, a new research path for the concept of molten salt reactor has been emerging, based on the U/Pu nuclear fuel cycle and a molten chloride salt. In this context, within the CHIMENE team, we are working with the CEA on the corrosion reactions of structural materials in such a media.

Molten salts are solvents whose chemical properties are very varied and depend on the nature of the salts entering into their composition. The installation of the laboratory for the study of molten salt reactor chemistry in Orsay and the associated experimental devices made it possible to broaden our field of expertise and to invest in other research themes related to the chemistry of molten salts, such as the pyrochemical treatment of solid fuel (ACSEPT and SACSESS European projects), the chemistry of heat transfer salts based on molten nitrates for sodium fast reactors or concentrated solar power plants (AREVA), the direct production of UF6(g) and its interaction with structural materials (AREVA), the carbonitriding of low carbon steels in molten carbonate media (HEF) or the dissolution of pulverulent metal waste in molten hydroxides (CEA and ORANO).

Highlights 2020-2021

  • The development of gas micro-chromatography for the analysis of gases installed on an electrochemical reactor with molten salts at high temperature.
  • The absence of corrosion of structural materials by controlling the redox potential of molten salt.
  • The influence of the nature of the crucible on the dissolution of Mg in molten hydroxides.

Collaborations

LPSC Grenoble, CEA Saclay, CEA Marcoule, CEA Cadarache, HEF, ORANO, JRC Karlsruhe, Valladolid University, ENGIE- Belgique, Terrestrial Energy, Seaborg Danemark

PhD thesis in progress

Hugo SAUZETStudy of nitrocarburizing process of steel in molten salts, CIFRE – HEF funding, Université Paris-Saclay, 2019 – 2022

Alexandre CHMAKOFFCorrosion mechanisms understanding in the environment of future reactors using molten salt fuel and coolant, CEA funding, Université Paris-Saclay, 2019-2022

Post-doctoral research in progress

Victor HAQUIN, Development of ICP-AES methodology for molten salt analysis in the frame of fluoride- based molten salt, SAMOSAFER project

Defended PhD thesis

Mickael ACHOURCorrosion mechanism of iron in liquid UF₆ at 80°C, ORANO funding, Université Paris-Saclay, 2018

Gabriela DURAN-KLIEStudy of uranium and iodine behavior in the molten fluorides LiF-ThF₄ at 650 ° C, Venezuela funding, Université Paris-Saclay, 2017

Thi-Kim-Khanh LEStudy of corrosion of steel in molten sodium nitrate at 340°C, AREVA funding, Université Paris-Saclay, 2016

David RODRIGUESActinide/lanthanide separation in molten salt media : application to the MSFR fuel reprocessing, CIFRE – RHODIA funding , Université Paris-Saclay, 2015

Marie LUCAS, Electrochemical microscopy in molten salt medium : experience, modeling and application to the study of corrosion, Ecole Doctorale Paris funding, Université Pierre et Marie Curie, 2013

Sébastien JASKIEROWICZFuel reprocessing of the fast molten salt reactor : actinides et lanthanides extraction, CIFRE – RHODIA funding, Université Paris-Saclay, 2012

Last publications

P. Soucek, D. Rodrigues, O. Beneš, S. Delpech , A. Rodrigues, R.J.M. Konings, “Electrochemical measurements of LiF-CaF2 -ThF4 melt and activity coefficient of ThF4 in LiF-CaF2 eutectic melt”, Electrochimica Acta, 381 (2021) 138

Michel Allibert, Elsa Merle, Sylvie Delpech, Delphine Gerardin, Daniel Heuer, Axel Laureau, Simon Moreau, “Preliminary proliferation study of the molten salt fast reactor”, EPJ Nuclear Science and Technology, 6 (2020) 5

Mickaël Achour, Laure Martinelli, Sylvie Chatain, Laurent Jouffret, Marc Dubois, Pierre Bonnet, Ania Selmi, Bertrand Morel and Sylvie Delpech, “Corrosion of iron in liquid uranium hexafluoride”, Corrosion engineering Science and Technology, 52 – 8 (2017) 611