HIGH-DENSITY, SOLID SOLUTION NUCLEAR FUEL AND FUEL BLOCK UTILIZING SAME

A nuclear fuel element for nuclear power reactor systems, especially very-high-temperature reactor (VHTR) systems with prismatic blocks, includes a core (12) formed from a high-density solid solution fissile material (16) that is substantially free of carbon and void space. Examples of high-density, solid solution fissile materials (16) are uranium oxide (UO2), urania-zirconia-calcia (UO2-ZrO2-CaO); uranium nitride (UN); uranium carbide (UC2), uranium suicide (U3Si2), and mixtures thereof. The nuclear fuel element is surrounded by cladding (14). Examples of suitable cladding materials include silicon carbide (SiC), zirconium carbide (ZrC), hafnium carbide (HfC), tantalum carbide (TaC, and mixtures thereof, and may comprise a multi-layer cladding, with inner layer (115) and outer layer (117). Their high density relative to conventional, e.g., TRISO-coated fuel particles, lowers enrichment requirements for fissile uranium loading. L'invention concerne un élément combustible nucléaire qui comprend un noyau formé par un matériau fissile à solution solide haute densité sensiblement exempt de carbone et d'espace vide. Une gaine entoure sensiblement le noyau.