Corrosion in molten chlorides - CEA developments and research program

Abstract

International audienceA French R&D program (CEA, CNRS, Orano) has been launched on molten salts cooled reactors which aims at assessing the feasibility of fast MSRs and confirm their potential assets. Chloride salts have been selected and in the French context (closed cycle, transmutation, Pu multirecycling), we focus on chlorides fast MSR with a focus on actinides conversion (reducing ultimate wastes). One of the major constraints on the use of molten chlorides is the corrosion behaviour of structural materials. To overcome this constraint, different approaches are performed with different time scales:- Evaluation of already available and /or qualified materials such as nickel base alloys but also high entropy alloys or ceramics.- Evaluation of different corrosion protection strategies: protective coatings, electrochemical potential control, chemistry control…- Evaluation of more innovative solutions: advanced manufacturing processes, smart materials, architectured materials…In the same time a large French research program has been launched together with CEA and CNRS to work on the global acceleration of materials discovery, the DIADEM (DIscovery Acceleration for the Deployment of Emerging Materials) project. In the frame of this large project which will be launched in 2022 for 8 years, shorter targeted projects have been already selected (duration of 3 years), as the A-DREAM project which is dedicated to the acceleration of the development of corrosion resistant materials in molten chlorides. For this, the A-DREAM project proposes an integrated approach implementing: (i) the digital design of materials/coatings, (ii) the high throughput synthesis of these materials and (iii) the implementation of an accelerated corrosion methodology. In this presentation, the French corrosion strategy for MSR will be presented together with results obtained