Nuclear fuel pellet with central burnable absorber

Patent metadata

Field	Value
Publication number	US-11049625-B2
Application number	US-201715819323-A
Country	US
Kind code	B2
Filing date	Nov 21, 2017
Priority date	Nov 25, 2016
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

The present invention relates to a sintered nuclear fuel pellet wherein one or more consolidated bodies of a burnable absorber are inserted inside, wherein the one or more consolidated bodies of the burnable absorber do not include nuclear fuel which includes UO2, and the one or more consolidated bodies of the burnable absorber are inserted into a radially central region of the sintered nuclear fuel pellet, such that the one or more consolidated bodies are surrounded by the nuclear fuel pellet without being exposed to an outside of the sintered nuclear fuel pellet. The present invention can optimize the regulation of excess reactivity by optimizing the self-shielding and the burning speed of the burnable absorber using one or more consolidated bodies the burnable absorber.

First claim

What is claimed is:

1. A sintered nuclear fuel pellet comprising nuclear fuel,
wherein the sintered nuclear fuel pellet includes a burnable absorber consisting of one or more consolidated bodies,
wherein the one or more consolidated bodies of the burnable absorber is inside of the nuclear fuel pellet,
wherein
the one or more consolidated bodies is in the nuclear fuel pellet at a volume fraction of 2˜20 percent volume by the total volume of the nuclear fuel pellet,
all of the one or more consolidated bodies do not comprise nuclear fuel, and
all of the one or more consolidated bodies are located in a radially central region of the nuclear fuel pellet,
such that all of the one or more consolidated bodies are surrounded by the nuclear fuel in all directions without the one or more consolidated bodies being exposed to an outside of the nuclear fuel pellet, and

wherein only the radially central region includes burnable absorber material,
such that area of the nuclear fuel pellet located outside of the radially central region is free of burnable absorber material.

2. The sintered nuclear fuel pellet according to claim 1 , wherein either a combustion speed or self-shielding effect of the burnable absorber, or both are controlled by regulating a size, shape, or insertion location of the one or more consolidated bodies of the burnable absorber.

3. The sintered nuclear fuel pellet according to claim 1 , wherein the one or more consolidated bodies of the burnable absorber includes Gd2O3; Er2O3; Gd2O3 stabilized with one or more selected from the group consisting of CeO2, In2O3, Y2O3, TiO2, ZrO2, Al2O3, and Y2O3-ZrO2 (yttria-stabilized zirconia); Er2O3 stabilized with one or more selected from the group consisting of CeO2, In2O3, Y2O3, TiO2, ZrO2, Al2O3, and Y2O3-ZrO2 (yttria-stabilized zirconia); or a combination thereof.

4. The sintered nuclear fuel pellet according to claim 3 , wherein the CeO2, In2O3, Y2O3, TiO2, ZrO2, Al2O3, and Y2O3-ZrO2 are included in Gd2O3 and Er2O3 at a concentration of 1˜60 weight %.

5. A method of manufacturing a sintered nuclear fuel pellet comprising the following steps:
forming one or more consolidated bodies of a burnable absorber;
inserting the one or more consolidated bodies in nuclear fuel;
forming a nuclear fuel-consolidated body composite by press-molding a mixture of the nuclear fuel and the one or more consolidated bodies; and
forming a sintered nuclear fuel pellet by sintering the nuclear fuel-consolidated body composite,

wherein the sintered nuclear fuel pellet includes the burnable absorber consisting of the one or more consolidated bodies,
wherein the one or more consolidated bodies of the burnable absorber is inside of the nuclear fuel pellet,
wherein
the one or more consolidated bodies is in the nuclear fuel pellet at a volume fraction of 2˜20 percent volume by the total volume of the nuclear fuel pellet,
all of the one or more consolidated bodies do not comprise nuclear fuel, and
all of the one or more consolidated bodies are located in a radially central region of the nuclear fuel pellet,
such that all of the one or more consolidated bodies are surrounded by the nuclear fuel in all directions without the one or more consolidated bodies being exposed to an outside of the nuclear fuel pellet, and

wherein only the radially central region includes burnable absorber material,
such that area of the nuclear fuel pellet located outside of the radially central region is free of burnable absorber material.

6. The method of manufacturing according to claim 5 , wherein the step of forming the one or more consolidated bodies of the burnable absorber comprises the following substeps:
homogenizing and mixing burnable absorber powder; and
press-molding the mixed burnable absorber powder.

7. The method of manufacturing according to claim 6 , wherein the step of press-molding the mixed burnable absorber powder comprises
a first press-molding at a pressure of 30 MPa˜100 MPa and
a second press-molding at a pressure of 200 MPa˜500 MPa by a hydrostatic press (CIP).

8. The method of manufacturing according to claim 6 ,
wherein the step of press-molding the mixed burnable absorber powder is performed once at a pressure of 100 MPa˜500 MPa.

9. The method of manufacturing according to claim 5 , wherein the step of forming the one or more consolidated bodies of the burnable absorber comprises the following substeps:
homogenizing and mixing burnable absorber powder; and
injecting the burnable absorber powder into a hole of a hollow green body of nuclear fuel, and pressing an inside of the hole.

10. The method of manufacturing according to claim 9 , wherein the hollow green body of nuclear fuel includes one or more materials selected from the group consisting of CeO2, In2O3, Y2O3, TiO2, ZrO2, Al2O3, and Y2O3-ZrO2.

11. The method of manufacturing according to claim 9 , wherein the step of pressing is performed by uniaxial pressing the inside of the hole at a pressure of 30 MPa˜100 MPa.

12. The method of manufacturing according to claim 9 , wherein the hollow green body of nuclear fuel is in the shape of a ring or a tube, and a diameter of the hollow is 1˜3 mm.

13. The method of manufacturing according to claim 9 , wherein the one or more consolidated bodies of the burnable absorber includes Gd2O3; Er2O3; Gd2O3 stabilized with one or more selected from the group consisting of CeO2, In2O3, Y2O3, TiO2, ZrO2, Al2O3, and Y2O3-ZrO2 (yttria-stabilized zirconia); Er2O3 stabilized with one or more selected from the group consisting of CeO2, In2O3, Y2O3, TiO2, ZrO2, Al2O3, and Y2O3-ZrO2 (yttria-stabilized zirconia); or a combination thereof.

14. The method of manufacturing according to claim 13 , wherein the one or more selected from the group consisting of CeO2, In2O3, Y2O3, TiO2, ZrO2, Al2O3, and Y2O3-ZrO2 (yttria-stabilized zirconia) are included in Gd2O3 or Er2O3 at a concentration of 3˜30 weight %.

Assignees

• Korea Advanced Inst Sci & Tech

Inventors

• Kim Yonghee
• Ryu Ho Jin
• Yahya Mohd Syukri Bin
• Mistarihi Qusai Mahmoud Mohammad
• Kim Chihyung

Classifications

• G21C21/02 Primary

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

• Y02E30/30

  Nuclear fission reactors · CPC title

• G21C3/045

  Pellets · CPC title

• G21C7/04

  of burnable poisons (burnable poisons in fuel rods G21C3/326) · CPC title

• 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