Granted Patent B2

US 10,522,255 · App. 15/618,305 · Granted Dec 31, 2019

Inventors: Martin van Staden (Annapolis, MD); Peter Pappano (Poolesville, MD)

Assignee: X-Energy, LLC

G21C1/07G21C3/044G21C21/02

Abstract

Claims (42)

1. A method of manufacturing a nuclear fuel element configured for use in a high-temperature gas cooled reactor core, the method comprising:

forming a base portion of the nuclear fuel element by depositing a powdered matrix material on a substrate, the powder matrix material comprising a mixture of a graphite material and a fibrous material;

depositing particles on the base portion in a predetermined pattern to form a first particle layer, by controlling the position of each particle in the first particle layer;

depositing the powdered matrix material on the first particle layer to form a first matrix layer;

depositing particles on the first matrix layer in a predetermined pattern to form a second particle layer, by controlling the position of each particle in the second particle layer;

depositing the powdered matrix material on the second particle layer to form a second matrix layer; and

forming a cap portion of the nuclear fuel element by depositing the matrix material comprising a mixture of a graphite material and a fibrous material on a particle layer,

wherein the particles comprise nuclear fuel particles.

2. The method of claim 1 , wherein:

the fibrous material comprises carbon nanotubes, silicon carbide fibers, or a combination thereof; and

the graphite material comprises graphite powder, graphite spheres, or a combination thereof.

3. The method of claim 1 , wherein the fibrous material comprises carbon nanotubes and silicon carbide fibers.

4. The method of claim 3 , wherein the powdered matrix material comprises, based on the total weight of the matrix material:

from about 1 wt % to about 64 wt % of the carbon nanotubes; and

from about 1 wt % to about 16 wt % of the silicon carbide fibers.

5. The method of claim 1 , wherein the powdered matrix material comprises, based on the total weight of the matrix material:

from about 20 wt % to about 99 wt % of the graphite material; and

from about 1 wt % to about 80 wt % of the fibrous material.

6. The method of claim 1 , further comprising mixing the graphite material and the fibrous material before depositing the powdered matrix material.

7. The method of claim 1 , wherein controlling the position of each particle within the first and second particle layers comprises:

loading particles in controlled positions on a deposition head;

disposing the deposition head over the base portion or the first matrix layer;

releasing the particles from the deposition head; and

pressing the particles into the base portion or the first matrix layer,

wherein the deposition head is a vacuum deposition head or an electrostatic deposition head.

8. The method of claim 1 , wherein:

depositing the powdered matrix material on the first particle layer to form a first matrix layer comprises printing a binder on a portion of the deposited matrix material to define the size and shape of the first matrix layer; and

depositing the powdered matrix material on the second particle layer to form a second matrix layer comprises printing a binder on a portion of the deposited matrix material to define the size and shape of the second matrix layer.

9. The method of claim 8 , further comprising:

pressing the first particle layer before forming the first matrix layer;

pressing the first matrix layer before forming the second particle layer;

pressing the second particle layer before forming the second matrix layer; and

pressing the second matrix layer before forming the cap portion.

10. The method of claim 1 , wherein forming a base portion and forming a cap portion each comprise:

A) depositing the powdered matrix material comprising a mixture of graphite material and fibrous material;

B) pressing the deposited matrix material;

C) printing a binder on the pressed matrix material; and

repeating operations A, B, and C; until the corresponding base portion or cap portion has a thickness ranging from 3 mm to 12 mm.

11. The method of claim 1 , wherein operation C comprises printing the binder in a pattern having the same shape as a cross-section of the nuclear fuel element.

12. The method of claim 1 , wherein the particles deposited in the first matrix layer and the second matrix layer comprise tri-structural-isotropic (TRISO) fuel particles that do not have an overcoat.

13. The method of claim 1 , wherein controlling the position of each particle within the first and second particle layers comprises positioning the particles in a fuel zone of the nuclear fuel element that is surrounded by a fuel-free shell of the nuclear fuel element formed of the matrix material.

14. The method of claim 1 , wherein the nuclear fuel element is a spherical fuel pebble suitable for use in a pebble bed high temperature gas cooled reactor.

Assignments (8)

Continuity (4)