Described herein are Uranium silicide materials as advanced nuclear fuel replacements for uranium dioxide fuel in light water reactors (LWRs) that have advantages over currently used uranium dioxide (UO.sub.2) via a substantially higher thermal conductivity and, thus, are capable of operating in a reactor at significantly lower temperatures for the same level of power production, plus the heat capacity of a silicide is lower than that of an oxide so that less heat is stored in the fuel that would need to be removed under accident conditions.

A type of composite material where the matrix material and additive are held together by covalently or non-covalently bound ligands is described. A particularly useful composite material covered by the present invention is a carbon nanotube-reinforced composite material where the matrix consists of a polymer, covalently attached to a linker, where said linker is non-covalently attached to the carbon nanotube.

Methods for the preparation of such composite materials are provided.

A type of composite material where the matrix material and additive are held together by covalently or non-covalently bound ligands is described. A particularly useful composite material covered by the present invention is a carbon nanotube-reinforced composite material where the matrix consists of a polymer, covalently attached to a linker, where said linker is non-covalently attached to the carbon nanotube. Methods for the preparation of such composite materials are provided.

A method for fabricating a ceramic matrix composite component having a deltoid region is provided. The method includes providing a porous ceramic preform. The porous ceramic preform includes a layer-to-layer weave of ceramic fibers that forms a modified layer-to-layer woven core and at least one 2-dimensional layer of ceramic fibers that is disposed adjacent to the modified layer-to-layer woven core. The porous ceramic preform is formed into a ceramic matrix composite body having the deltoid region such that the modified layer-to-layer woven core extends through the deltoid region.

Provided is a nuclear fuel pellet having excellent impact resistance, the pellet being prepared with UO.sub.2 powder and having a cylindrical shape with a height of 9 to 13 mm and a horizontal cross-section diameter of 8 to 8.5 mm, and including: at each of a top surface and a bottom surface thereof, a dish configured as a spherical groove shape having a predetermined curvature and a groove diameter of 4.8 to 5.2 mm on a center; a shoulder configured as an annular plane along a rim of the dish; and a chamfer configured as a shape in which a corner is chamfered along a rim of the shoulder, wherein a width of the shoulder is 0.20 mm to 0.80 mm, and an angle between the chamfer and a horizontal plane is a 14-degree angle to 18-degree angle.

A method for producing microencapsulated fuel pebble fuel more rapidly and with a matrix that engenders added safety attributes. The method includes coating fuel particles with ceramic powder; placing the coated fuel particles in a first die; applying a first current and a first pressure to the first die so as to form a fuel pebble by direct current sintering. The method may further include removing the fuel pebble from the first die and placing the fuel pebble within a bed of non-fueled matrix ceramic in a second die; and applying a second current and a second pressure to the second die so as to form a composite fuel pebble.

A method for producing microencapsulated fuel pebble fuel more rapidly and with a matrix that engenders added safety attributes. The method includes coating fuel particles with ceramic powder; placing the coated fuel particles in a first die; applying a first current and a first pressure to the first die so as to form a fuel pebble by direct current sintering. The method may further include removing the fuel pebble from the first die and placing the fuel pebble within a bed of non-fueled matrix ceramic in a second die; and applying a second current and a second pressure to the second die so as to form a composite fuel pebble.

A method for producing microencapsulated fuel pebble fuel more rapidly and with a matrix that engenders added safety attributes. The method includes coating fuel particles with ceramic powder; placing the coated fuel particles in a first die; applying a first current and a first pressure to the first die so as to form a fuel pebble by direct current sintering. The method may further include removing the fuel pebble from the first die and placing the fuel pebble within a bed of non-fueled matrix ceramic in a second die; and applying a second current and a second pressure to the second die so as to form a composite fuel pebble.

A method for producing microencapsulated fuel pebble fuel more rapidly and with a matrix that engenders added safety attributes. The method includes coating fuel particles with ceramic powder; placing the coated fuel particles in a first die; applying a first current and a first pressure to the first die so as to form a fuel pebble by direct current sintering. The method may further include removing the fuel pebble from the first die and placing the fuel pebble within a bed of non-fueled matrix ceramic in a second die; and applying a second current and a second pressure to the second die so as to form a composite fuel pebble.

A nuclear fuel includes uranium(IV) oxide (UO.sub.2) and manganese (Mn) as a dopant. The Mn dopant may be present in the fuel in an amount up to the solubility limit for Mn under a given set of conditions, for example, about 0.01 wt % to about 1 wt %. The nuclear fuel is substantially free of aluminum (Al). The nuclear fuel exhibits enhanced grain size development during sintering temperatures as low at 1400 K due to an increase in uranium sub-lattice vacancies induced by dissolution of the Mn dopant at interstitial defect sites. The Mn-doped nuclear fuel exhibits improved grain sizes at lower temperatures compared to Cr-, Al-, and undoped UO.sub.2, and therefore desirably exhibits lower fission gas release and higher plasticity, reducing the chances of fuel rod failure.