This paper presents several studies for the design and optimization of a 3GWth breeder Molten Salt Fast Reactor using chloride salts and the uranium cycle (Cl-MSFR). Results lead to a configuration of 45m3 of NaCl-depUCl3-(spent UOX fuel TRUs)Cl3 for the fuel salt, along with a fertile blanket of 80cm of width filled with NaCl-depUCl3 in which a small amount of spent MOX fuel TRUs is dissolved for spent MOX reuse and proliferation resistance. A reprocessing scheme dedicated to the cleaning of these chloride salts is proposed. Finally, preliminary studies on Cl-MSFR deployment don't show any constraints on matter availability and present a good synergy with PWRs.