An installation for converting the chemical composition of nuclear material so as to facilitate its further use or processing, in particular to provide feed material for isotope separation and/or reactor fuel fabrication. To produce material for isotope separation, natural uranium ore concentrates or uranium oxides from reprocessing are converted into uranium hexafluoride (UF₆). To produce material for fuel fabrication, the following conversions are carried out: U₃O₈ or UF₆ to uranium dioxide (UO₂); U or Pu nitrate to oxide; and U or Pu oxides to metal. Operations to convert UF₆ to UO₂ normally are performed in conversion sections of uranium fuel fabrication plants, while conversions of U or Pu nitrates to oxides normally are performed in conversion sections of reprocessing plants or in mixed oxide (MOX) fuel fabrication plants.