Methods for making a porous nuclear fuel element

摘要

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.

主权项

1. A process for fabricating a porous nuclear fuel element, comprising:
a) providing a skeletal structure comprising interconnected pores; and b) performing chemical vapor infiltration (CVI) of the skeletal structure with a nuclear fuel material; wherein the process of chemical vapor infiltration comprises:
i) heating the skeletal structure;ii) forcing a precursor gas through the heated skeletal structure;iii) decomposing the precursor gas inside of the heated skeletal structure; andiv) condensing the decomposed gases from the vapor state as a solid deposited on internal and external surfaces of the skeletal structure to form a skeletal structure comprising solid fuel ligaments;wherein the skeletal structure comprises a reticulated vitreous or glassy carbon foam.