Nuclear fuel pebble and method of manufacturing the same
A method of manufacturing nuclear fuel elements may include: forming a base portion of the fuel element by depositing a powdered matrix material including 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 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 positions of each particle in the second particle layer; depositing the matrix material on the second particle layer to form a second matrix layer; and forming a cap portion of the fuel pebble by depositing the matrix material. The particles in the first particle layer and the second particle layer include nuclear fuel particles.
1. A nuclear fuel element formed by a method comprising:
forming a base portion of the nuclear fuel element by depositing a powdered matrix material on a substrate, the powdered 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 nuclear fuel element of claim 1 , wherein the nuclear fuel element comprises:
a fuel zone comprising the first and second particle layers; and
a fuel-free shell surrounding the fuel zone and comprising the matrix material.
3. The nuclear fuel element of claim 2 , wherein:
the particles comprise one or more of fissile particles, breeder particles, and burnable poison particles;
the fuel zone comprises a central region and a peripheral region surrounding the central region; and
positions of particles in the first and second particle layers are controlled so that the central region has a higher burnable poison particle to fissile particle ratio than the peripheral region.
4. The nuclear fuel element of claim 2 , wherein:
the nuclear fuel element is a spherical fuel pebble having a diameter ranging from about 5 cm to about 7 cm; and
the fuel-free shell has a thickness ranging from about 0.3 cm to about 1.5 cm.
5. The nuclear fuel element of claim 1 , wherein:
the particles of the first particle layer are disposed in a first plane;
the particles of the second particle layer are disposed in a second plane that is substantially parallel to the first plane; and
the particles of the first particle layer do not overlap the particles of the second particle layer in a direction substantially perpendicular to the first and second planes.