Methods of forming triuranium disilicide structures, and related fuel rods for light water reactors

Patent metadata

Field	Value
Publication number	US-10109381-B2
Application number	US-201514746279-A
Country	US
Kind code	B2
Filing date	Jun 22, 2015
Priority date	Jun 22, 2015
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A method of forming a triuranium disilicide structure comprises forming a mixture comprising uranium particles and silicon particles. The mixture is pressed to form a compact comprising the uranium particles and the silicon particles. The compact is subjected to an arc melting process to form a preliminary triuranium disilicide structure. The preliminary triuranium disilicide structure is subjected to a comminution process to form a fine triuranium disilicide powder. The fine triuranium disilicide powder is pressed to form a green triuranium disilicide structure. The green triuranium disilicide structure is then sintered. Additional methods of forming a triuranium disilicide structure are also described, as are fuel rods for light water reactors.

First claim

What is claimed is:

1. A method of forming an U 3 Si 2 structure, comprising:
forming a mixture comprising uranium particles and silicon particles;
pressing the mixture to form a compact comprising the uranium particles and the silicon particles;
subjecting the compact to an arc melting process to form a preliminary U 3 Si 2 structure;
subjecting the preliminary U 3 Si 2 structure to a comminution process to form a fine U 3 Si 2 powder;
pressing the fine U 3 Si 2 powder to form a green U 3 Si 2 structure; and
sintering the green U 3 Si 2 structure.

2. The method of claim 1 , wherein forming a mixture comprises:
segmenting at least one larger uranium structure into smaller uranium structures;
subjecting the smaller uranium structures to at least one hydriding/dehydriding process to form the uranium particles; and
combining at least some of the uranium particles with the silicon particles to form the mixture, the mixture comprising from about 92.7 wt % uranium to about 92.5 wt % uranium and from about 7.3 wt % silicon to about 7.5 wt % silicon.

3. The method of claim 1 , wherein pressing the mixture to form a compact comprises:
providing at least a portion of the mixture into a cavity of a container; and
applying a pressure within a range of from about 150 MPa to about 300 MPa to the at least a portion of the mixture within the cavity.

4. The method of claim 1 , wherein subjecting the compact to an arc melting process comprises:
positioning the compact over a surface of a conductive structure;
positioning an electrode over the compact;
applying electric current to the electrode to form an arc between the electrode and the conductive structure and form a molten U 3 Si 2 structure; and
cooling the molten U 3 Si 2 structure to form the preliminary U 3 Si 2 structure.

5. The method of claim 4 , further comprising:
inverting the preliminary U 3 Si 2 structure;
positioning the inverted preliminary U 3 Si 2 structure over the surface of a conductive structure;
positioning an electrode over the inverted preliminary U 3 Si 2 structure;
applying additional electrical current to the electrode over the inverted preliminary U 3 Si 2 structure to form another arc between the electrode and the conductive structure over which the inverted preliminary U 3 Si 2 structure is positioned and form another molten U 3 Si 2 structure; and
cooling the another molten U 3 Si 2 structure to reform the preliminary U 3 Si 2 structure.

6. The method of claim 1 , further comprising heating the compact to a temperature within a range of from about 800° C. to about 1450° C. prior to subjecting the compact to the arc melting process.

7. The method of claim 1 , wherein subjecting the preliminary U 3 Si 2 structure to a comminution process comprises:
subjecting the preliminary U 3 Si 2 structure to an initial milling process to form an initial U 3 Si 2 powder comprising U 3 Si 2 particles each independently exhibiting a particle size less than or equal to about 5 mm; and
subjecting the initial U 3 Si 2 particles to an additional milling process to form the fine U 3 Si 2 powder, the fine U 3 Si 2 powder comprising fine U 3 Si 2 particles exhibiting an average particle size within a range of from about 0.5 μm to about 10 μm.

8. The method of claim 7 , wherein subjecting the preliminary U 3 Si 2 structure to an initial milling process to form an initial U 3 Si 2 powder comprises hammer milling the preliminary U 3 Si 2 structure.

9. The method of claim 7 , wherein subjecting the initial U 3 Si 2 particles to an additional milling process comprises:
subjecting the initial U 3 Si 2 particles to a first planetary milling process to form smaller U 3 Si 2 particles each independently exhibiting a particle size less than or equal to about 50 μm; and
subjecting the smaller U 3 Si 2 particles to at least one second planetary milling process to form the fine U 3 Si 2 particles.

10. The method of claim 9 , wherein subjecting the initial U 3 Si 2 particles to a first planetary milling process comprises:
introducing the initial U 3 Si 2 particles and a first milling media into a milling container; and
pulverizing the initial U 3 Si 2 particles using the first milling media and the milling container to form the smaller U 3 Si 2 particles.

11. The method of claim 10 , wherein subjecting the smaller U 3 Si 2 particles to at least one second planetary milling process comprises:
separating the smaller U 3 Si 2 particles from the first milling media;
providing the separated smaller U 3 Si 2 particles and a second milling media into a milling container, the second milling media having an average particle size less than that of the first milling media; and
pulverizing the smaller U 3 Si 2 particles using the second milling media and the milling container to form the fine U 3 Si 2 particles.

12. The method of claim 11 , further comprising:
selecting the first milling media to comprise hard material particles having an average particle size less than or equal to about 5 mm; and
selecting the second milling media to comprise additional hard material particles having an average particle size less than or equal to about 1 mm.

13. The method of claim 9 , further comprising combining the initial U 3 Si 2 particles with at least one lubricant prior to subjecting the initial U 3 Si 2 particles to the first planetary milling process.

14. The method of claim 13 , further comprising subjecting the fine U 3 Si 2 particles to a volatilization process to substantially remove remaining portions of the at least one lubricant from the fine U 3 Si 2 particles.

15. The method of claim 1 , wherein pressing the fine U 3 Si 2 powder comprises:
providing the fine U 3 Si 2 powder into a die cavity; and
applying pressure to the fine U 3 Si 2 powder within the die cavity to form the green U 3 Si 2 structure, the green U 3 Si 2 structure having a density within a range of from about 7.32 g/cm 3 to about 7.93 g/cm 3 .

16. The method of claim 1 , further comprising combining the fine U 3 Si 2 powder with at least one binder material prior to pressing the fine U 3 Si 2 powder to form the green U 3 Si 2 structure.

17. The method of claim 1 , wherein sintering the green U 3 Si 2 structure comprises heating the green U 3 Si 2 structure to a temperature within a range of from about 1200° C. to about 1500° C. under negative pressure or in an inert atmosphere for a sufficient amount of time to form a sintered U 3 Si 2 structure having a density greater than or equal to about 11.47 g/cm 3 .

18. The method of claim 17 , further comprising subjecting at least one of the green U 3 Si 2 structure or the sintered U 3 Si 2 structure to at least one machining process to reduce at least one dimension thereof.

19. The method of claim 18 , wherein subjecting at least one of the green U 3 Si 2 structure or the sintered U 3 Si 2 structure to at least one machining process comprises subjecting the sintered U 3 Si 2 structure to a centerless grinding process.

20. A method of forming an U 3 Si 2 structure, comprising:
forming a compact comprising from about 92.5 wt % to about 92.7 wt % uranium particles each independently exhibiting a particle size less than or equal to about 300 μm and from about 7.3 wt % to about 7.5 wt % silicon particles each independently exhibiting a particle size less than or equal to about 150 μm;
subjecting the compact to an arc melting process to form a preliminary U 3 Si 2 structure;
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Assignees

• Battelle Energy Alliance Llc
• Battelle Energy Alliance Llc

Inventors

• Harp Jason Michael
• Lessing Paul Alan
• Hoggan Rita Elaine

Classifications

• G21C3/58

  Solid reactor fuel {Pellets made of fissile material} · CPC title

• G21C21/02 Primary

  Manufacture of fuel elements or breeder elements contained in non-active casings · CPC title

• C04B2235/6562

  Heating rate · CPC title

• C04B2235/5445

  submicron sized, i.e. from 0,1 to 1 micron · CPC title

• C04B35/6261

  Milling · CPC title