Method of manufacturing a reinforced nuclear fuel cladding using an intermediate thermal deposition layer

Patent metadata

Field	Value
Publication number	US-2018254114-A1
Application number	US-201715450167-A
Country	US
Kind code	A1
Filing date	Mar 6, 2017
Priority date	Mar 6, 2017
Publication date	Sep 6, 2018
Grant date	—

Abstract

A method is described that includes the steps of making a thin walled Zr alloy tube, loading nuclear fuel pellets into the tube, compressing the tube onto the fuel pellets to substantially reduce free space around the fuel pellets, positioning end plugs at each of two ends of the tube, filling the tube with a heat transferring gas, and coating the compressed tube with a corrosion resistant material using a thermal deposition process, such as cold spray, before inserting the tube into a pre-formed SiC composite cover having at least one closed end.

First claim

What is claimed is:

1 . A method for making a fuel rod comprising:
loading a tube having a first open end and a second open end with nuclear fuel; compressing the fuel-loaded tube around the fuel to reduce free space in the tube; closing at least one of the first and second ends of the tube; filling the fuel-loaded tube with a gas suitable for transferring heat; and, covering the compressed tube with a pre-formed protective cover.

2 . The method recited in claim 1 further comprising closing each of the first and second open ends of the tube with a first and second end plug, respectively, wherein at least one of the first and second end plugs has a gas port.

3 . The method recited in claim 2 wherein each open end is closed prior to filling the fuel-loaded tube with gas through the gas port.

4 . The method recited in claim 1 wherein compressing the tube comprises placing the tube into a chamber, and pressurizing the chamber with a fluid to exert sufficient force against the tube to press the tube against the fuel residing in the tube.

5 . The method recited in claim 4 wherein the fluid is one of a liquid or a compressed gas.

6 . The method recited in claim 4 wherein the chamber is a cold isostatic press.

7 . The method recited in claim 6 wherein the chamber is a dry bag cold isostatic press wherein a flexible membrane separates the fluid from the tube.

8 . The method recited in claim 6 wherein the chamber is a wet bag cold isostatic press wherein the fluid contacts the tube.

9 . The method recited in claim 4 wherein the inwardly directed pressure is applied with a roller around at least a portion of the tube.

10 . The method recited in claim 1 further comprising applying a corrosion resistant coating on the compressed tube before covering the compressed tube with a pre-formed cover.

11 . The method recited in claim 10 wherein the corrosion resistant coating is applied with a thermal deposition process.

12 . The method recited in claim 11 wherein the thermal deposition process is a cold spray process.

13 . The method recited in claim 12 wherein the cold spray process comprises:
heating a pressurized carrier gas to a temperature between 100° C. and 1200° C.;
adding particles to the heated carrier gas; and
spraying the carrier gas and entrained particles at a velocity of 800 to 4000 ft./sec. (about 243.84 to 1219.20 meters/sec.).

14 . The method recited in claim 13 wherein the carrier gas is selected from the group consisting of nitrogen (N 2 ), hydrogen (H 2 ), argon (Ar), carbon dioxide (CO 2 ), and helium (He) and combinations thereof.

15 . The method recited in claim 13 wherein the particles are selected from the group consisting of chromium, chromium alloys, and combinations thereof.

16 . The method recited in claim 10 wherein the corrosion resistant coating comprises applying dual layer.

17 . The method recited in claim 16 wherein applying the dual layer comprises applying an interlayer using the cold spray process and applying an outer layer using the cold spray process, wherein the particles used to form the interlayer are transition metal particles selected from the group consisting of molybdenum (Mo), niobium (Nb), tantalum (Ta), tungsten (W) and combinations thereof, and the particles used to form the outer layer are selected from the group consisting of chromium, chromium alloys, and combinations thereof.

18 . The method recited in claim 1 wherein the tube is made of a Zr alloy.

19 . The method recited in claim 1 wherein the pre-formed protective cover is made of a SiC composite material.

20 . The method recited in claim 1 wherein the gas is selected from the group consisting of H 2 , He, and combinations thereof.

21 . The method recited in claim 1 wherein the fuel comprises stacked pellets of fissile material.

22 . The method recited in claim 21 wherein the diameter of the end plugs are about the same diameter as that of the pellets.

23 . A method for making a fuel rod comprising:
providing a hollow tube having top and bottom open ends and inner and outer surfaces; stacking fissile material into the hollow tube; compressing the tube against the stacked fissile material to reduce available free space between the fissile material and the inner surface of the tube; closing at least one of the top and bottom ends of the tube with an end plug, at least one end plug having a gas port therethrough; adding a gas suitable for heat transfer to the tube through the gas port in the end plug; closing the port; applying a corrosion resistant coating to the outer surface of the compressed tube; providing a pre-formed cover; and, placing the coated compressed tube into the pre-formed cover.

24 . The method recited in claim 23 wherein compressing the tube comprises placing the tube into a chamber, and pressurizing the chamber with a fluid to exert sufficient force against the tube to press the tube against the fissile material residing in the tube.

25 . The method recited in claim 24 wherein the fluid is one of a liquid or a compressed gas.

26 . The method recited in claim 25 wherein the chamber is a cold isostatic press.

27 . The method recited in claim 26 wherein the chamber is a dry bag cold isostatic press wherein a flexible membrane separates the fluid from the tube.

28 . The method recited in claim 26 wherein the chamber is a wet bag cold isostatic press wherein the fluid contacts the tube.

29 . The method recited in claim 24 wherein the inwardly directed pressure is applied with a roller around at least a portion of the tube.

30 . The method recited in claim 23 wherein the corrosion resistant coating is applied by a thermal deposition process.

31 . The method recited in claim 30 wherein the thermal deposition process is a cold spray process comprising:
heating a pressurized carrier gas selected from the group consisting of nitrogen (N 2 ), hydrogen (H 2 ), argon (Ar), carbon dioxide (CO 2 ), and helium (He) and combinations thereof to a temperature between 100° C. and 1200° C.;
adding particles for forming an outer layer, the outer layer particles selected from the group consisting of chromium, chromium alloys, and combinations thereof to the heated carrier gas; and
spraying the carrier gas and entrained particles at a velocity of 800 to 4000 ft./sec. (about 243.84 to 1219.20 meters/sec.).

32 . The method recited in claim 31 wherein the corrosion resistant coating comprises applying dual layers, the dual layers comprised of an interlayer applied by a cold spray process before application of the outer layer, wherein the particles of the interlayer are transition metal particles selected from the group consisting of molybdenum (Mo), niobium (Nb), tantalum (Ta), tungsten (W) and combinations thereof.

33 . A cladding tube for a fuel rod in a nuclear reactor comprising:
a cladding tube formed from a zirconium alloy and having an exterior corrosion resistant coating comprised of an inner coating selected from the group consisting of a Mo, Ta, W, and Nb, and an outer coating selected from the group consisting of chromium, a chromium alloy, and combinations thereof; a plurality of nuclear fuel pellets stacked within the cladding tube; the claddi

Assignees

• Westinghouse Electric Co Llc

Inventors

• Lahoda Edward J
• Mueller Andrew J

Classifications

• G21C3/20

  with coating on fuel or on inside of casing; with non-active interlayer between casing and active material {with multiple casings or multiple active layers} · CPC title

• G21C21/02 Primary

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

• G21C3/042

  Fuel elements comprising casings with a mass of granular fuel with coolant passages through them · CPC title

• G21C3/045

  Pellets · CPC title

• G21C3/10 Primary

  End closures {; Means for tight mounting therefor} · CPC title