This disclosure describes systems and methods for synthesizing UCl3 from UCl4. These systems and methods may also be used to directly synthesize binary and ternary embodiments of uranium salts of chloride usable as nuclear fuel in certain molten salt reactor designs. The systems and methods described herein are capable of synthesizing any desired uranium chloride fuel salt that is a combination of UCl4, UCl3 and one or more non-fissile chloride compounds, such as NaCl. In particular, the systems and methods described herein are capable of synthesizing any UCl3—UCl4—NaCl or UCl3—NaCl fuel salt composition from UCl4—NaCl.