Electro-synthesis of uranium chloride fuel salts

Patent metadata

Field	Value
Publication number	US-2020251231-A1
Application number	US-202016782652-A
Country	US
Kind code	A1
Filing date	Feb 5, 2020
Priority date	Aug 10, 2016
Publication date	Aug 6, 2020
Grant date	—

Abstract

This disclosure describes systems and methods for synthesizing UCl 3 from UCl 4 . 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 UCl 4 , UCl 3 and one or more non-fissile chloride compounds, such as NaCl. In particular, the systems and methods described herein are capable of synthesizing any UCl 3 —UCl 4 —NaCl or UCl 3 —NaCl fuel salt composition from UCl 4 —NaCl.

First claim

What is claimed is:

1 . A method for synthesizing UCl 3 comprising:
providing a quantity of fuel salt, the fuel salt having a first amount of UCl 4 ; melting the quantity of fuel salt; and applying an electric current to the fuel salt, thereby reducing at least some UCl 4 to UCl 3 .

2 . The method of claim 1 further comprising:
applying the electric current to the fuel salt for a first length of time sufficient to reduce all of the UCl 4 to UCl 3 .

3 . The method of claim 1 further comprising:
applying the electric current to the fuel salt at an amperage and for a second length of time, wherein the amperage of the applied electric current over the second length of time is stoichiometrically calculated to create a target amount of UCl 3 .

4 . The method of claim 3 wherein applying the electric current to the fuel salt comprises:
applying the electric current to the fuel salt at a constant amperage for the second length of time.

5 . The method of claim 3 further comprising:
identifying a desired final ratio of UCl 3 to UCl 4 to be obtained in the quantity of fuel salt;
determining the target amount of UCl 3 to be created based on the desired final ratio and the quantity of fuel salt;
stoichiometrically determining the amperage and second length of time for the applied electric current based on the target amount of UCl 3 to be created; and
applying the electric current at the stoichiometrically determined amperage for the second length of time, thereby creating a fuel salt having the desired final ratio of UCl 3 to UCl 4 .

6 . The method of claim 3 wherein the stoichiometric amount of electric current is calculated to reduce all of the UCl 4 to UCl 3 .

7 . The method of claim 1 wherein the fuel salt is at least 99.9% UCl 4 .

8 . The method of claim 1 wherein the fuel salt is a mixture of UCl 4 and at least one non-fissile chloride compound.

9 . The method of claim 8 wherein the at least one non-fissile chloride compound is one or more of NaCl, MgCl 2 , CaCl 2 , BaCl 2 , KCl, SrCl 2 , VCl 3 , CrCl 3 , TiCl 4 , ZrCl 4 , ThCl 4 , AcCl 3 , NpCl 4 , AmCl 3 , LaCl 3 , CeCl 3 , PrCl 3 and/or NdCl 3 .

10 . The method of claim 8 wherein the at least one non-fissile chloride compound is only NaCl.

11 . The method of claim 1 wherein applying the electric current further comprises:
passing the electric current between at least one anode and at least one cathode submerged in the molten fuel salt.

12 . The method of claim 8 further comprising:
selecting an electric potential based on a temperature and pressure of the fuel salt to preferentially reduce the UCl 4 to UCl 3 without reducing the at least one non-fissile chloride compound; and
generating the selected electric potential between the at least one anode and the at least one cathode.

13 . The method of claim 1 further comprising:
maintaining the fuel salt in a molten state while applying the electric current to the fuel salt.

14 . The method of claim 13 wherein the maintaining the fuel salt in a molten state comprises:
monitoring the electric current applied to the fuel salt; and
changing one or both of the temperature or pressure of the fuel salt based on the monitored electric current.

15 . The method of claim 1 further comprising:
collecting Cl 2 generated by reducing the UCl 4 in the fuel salt to UCl 3 .

16 . The method of claim 15 wherein collecting Cl 2 comprises:
containing the fuel salt in a closed vessel while applying the electric current to the fuel salt;
removing gas evolved during the applying operation from the closed vessel;
separating Cl 2 in the removed gas from UCl 4 in the removed gas; and
returning the UCl 4 to the closed vessel.

17 . The method of claim 16 wherein separating the Cl 2 and UCl 4 comprises:
condensing the UCl 4 in the removed gas into liquid UCl 4 ; and
returning the liquid UCl 4 to the closed vessel.

18 . The method of claim 1 further comprising:
agitating the fuel salt while applying the electric current to the fuel salt.

19 . A method for synthesizing a UCl 3 —UCl 4 —NaCl fuel salt comprising:
providing an amount of UCl 4 —NaCl salt;
melting the UCl 4 —NaCl salt; and
reducing a portion of the UCl 4 in the UCl 4 —NaCl salt to UCl 3 by applying an electric current to the UCl 4 —NaCl salt, thereby creating the UCl 3 —UCl 4 —NaCl fuel salt.

20 . A system for the synthesis of UCl 3 from UCl 4 comprising:
a vessel having an interior wall defining an electrolysis chamber capable of holding molten UCl 3 and UCl 4 , the interior wall material unreactive with UCl 4 and UCl 3 at temperatures from 350-900° C. and pressures between 0.5 and 10 atm; at least one cathode and at least one anode in electrolysis chamber, the at least one cathode and at least one anode made of material unreactive with UCl 4 and UCl 3 at temperatures from 350-900° C. and pressures between 0.5 and 10 atm; a power source connected to the at least one cathode and at least one anode, the power source capable of creating a potential and applying electric current between the at least one cathode and at least one anode; and a system controller connected to the power source to control the potential and electric current from the power source between the at least one cathode and at least one anode, the system controller configured to maintain the potential between the at least one cathode and at least one anode within a range that reduces U 4+ to U 3+ without reducing U 3+ .

Assignees

• Terrapower Llc

Inventors

• Czerwinski Ken
• El-Dasher Bassem S
• Kerlin William M
• Unger Aaron J

Classifications

• C25B9/00

  Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features · CPC title

• C25B1/00

  Electrolytic production of inorganic compounds or non-metals · CPC title

• C25B11/04

  characterised by the material · CPC title

• Y02E30/30

  Nuclear fission reactors · CPC title

• C01G43/08 Primary

  Chlorides · CPC title