| Abstract: | Porous nuclear fuel elements for use in advanced high temperature
gas-cooled nuclear reactors (HTGR's), and to processes for fabricating
them. Advanced uranium bi-carbide, uranium tri-carbide and uranium
carbonitride nuclear fuels can be used. These fuels have high melting
temperatures, high thermal conductivity, and high resistance to erosion
by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be
fabricated using chemical vapor infiltration (CVI) to simultaneously
deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a
single CVI step. By using CVI, the nuclear fuel may be deposited inside
of a highly porous skeletal structure made of, for example, reticulated
vitreous carbon foam. |