[en] The Solvent Mineralization facility (MDS) at the La Hague site in France has been designed to condition spent solvent distillation residues as a solid waste. Active start-up of the facility is described and the results of the first solvent mineralization campaigns are presented. Since entering service in early 1998, the MDS facility has demonstrated the feasibility of operating a facility to condition reprocessing solvent residues in a stabilized form approved by waste disposal authorities, while generating only low releases with negligible radioactivity. Application of the MDS process to the disposal of solvent backlogs of nuclear production or research centers is discussed. (authors)