# US 2014/0192949 A1 · Nuclear reactor fuel element having silicon carbide multilayered cladding and thoria-based fissionable fuel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192949 A1 - Document ID: US20140192949A1 - Status: Published application - Kind: A1 - Application number: 14/126,614 - Filed: 2012-06-18 - Published: 2014-07-10 - Earliest claimed: 2011-06-16 - Assignees: Thor Energy AS; Ceramic Tubular Products, LLC - Inventors: Herbert Feinroth; Gregory T. Markham; Eugene Shwageraus; Julian F. Kelly - Web page: https://patentgrep.com/patent/US20140192949A1 ## CPC - G21C 3/07: characterised by their material, e.g. alloys - C04B 35/51: based on compounds of actinides ({non-oxide actinide compounds C04B35/5158;} nuclear fuel materials G21C3/62) - C04B 35/565: based on silicon carbide - C04B 35/62873: {Carbon} - C04B 35/80: Fibres, filaments, whiskers, platelets, or the like - G21C 3/06: Casings; Jackets - G21C 3/10: End closures {; Means for tight mounting therefor} - C04B 2235/5244: Silicon carbide - C04B 2235/5264: characterised by the diameter of the fibers - C04B 2235/77: Density - C04B 2235/94: Products characterised by their shape - Y02E 30/30: Nuclear fission reactors - G21C: NUCLEAR REACTORS (fusion reactors, hybrid fission-fusion reactors G21B; nuclear explosives G21J) - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A nuclear fuel element for use in water-cooled nuclear power reactors. The fuel element includes a multilayered silicon carbide cladding tube. The multilayered silicon carbide cladding tube preferably includes an inner layer and a central layer. Also, in one embodiment, the ends further include hermetically sealed end caps. The cladding tube is sized to receive a stack of individual fissionable fuel pellets. In one embodiment, the fuel pellets comprise a mixture of thorium oxide and plutonium oxide. ## Claims ### Claim at position 1 1-5. (canceled) ### Claim 6 In a nuclear fuel element for use in water-cooled, thorium-based nuclear power reactors, the improvement comprising: (a) a multilayered silicon carbide cladding tube, said multilayered silicon carbide cladding tube including (i) an inner layer and (ii) a central layer; and (b) hermetically sealed end caps, wherein said end caps are formed of high-density silicon carbide. ### Claim 7 (depends on 6) The fuel element according to claim 6, wherein said inner layer is a monolith layer. ### Claim 8 (depends on 7) The fuel element according to claim 7, wherein said inner monolith layer is formed by chemical vapor deposition. ### Claim 9 (depends on 6) The fuel element according to claim 6, wherein said central layer is a composite of silicon carbide surrounded by a silicon carbide matrix. ### Claim 10 (depends on 9) The fuel element according to claim 9, wherein said central composite layer includes silicon carbide fibers. ### Claim 11 (depends on 10) The fuel element according to claim 10, wherein said silicon carbide fibers are in the form of a tow that includes between about 500 and about 1600 fibers having between about 8 and about 14 microns in diameter. ### Claim 12 (depends on 11) The fuel element according to claim 11, wherein said silicon carbide fibers include a carbon interface coating thickness of between about 0.1 and about 1 micron. ### Claim 13 (depends on 6) The fuel element according to claim 6, further including an outer monolith layer. ### Claim 14 (depends on 13) The fuel element according to claim 13, wherein said outer monolith layer is formed by chemical vapor infiltration or by chemical vapor deposition. ### Claim 15 (depends on 13) The fuel element according to claim 13, wherein said outer monolith layer has a thickness between about 3 and about 10 mils. ### Claim 16 (depends on 6) The fuel element according to claim 6, wherein said multilayer silicon carbide cladding tube is substantially formed of stoichiometric beta silicon carbide crystals that are resistant to damage by neutron radiation. ### Claim 17 (canceled) ### Claim 18 (depends on 6) The fuel element according to claim 6, wherein said end caps are substantially formed of stoichiometric beta silicon carbide crystals that are resistant to damage by neutron radiation. ### Claim 19 (depends on 6) The fuel element according to claim 6, wherein said multilayer silicon carbide cladding tube is between about 1.5 and about 14 feet in length, with a tube wall thickness between about 20 and about 50 mils and with a tube outside diameter between about 0.25 and about 0.5 inches. ### Claim 20 A nuclear fuel element for use in water-cooled nuclear power reactors, said fuel element comprising: (a) a multilayered silicon carbide cladding tube, said multilayered silicon carbide cladding tube including (i) an inner layer and (ii) a central layer; (b) hermetically sealed end caps, wherein said end caps are formed of high-density silicon carbide; and (c) a stack of individual fissionable fuel pellets, wherein said fuel pellets comprise a mixture of thorium oxide and plutonium oxide. ### Claim 21 (depends on 20) The fuel element according to claim 20, wherein said fuel pellets further include uranium 233 oxide substituted for the plutonium oxide and mixtures thereof. ### Claim 22 (depends on 21) The fuel element according to claim 21, wherein said fuel pellets include thorium oxide, plutonium oxide, uranium oxide, americium oxide, neptunium oxide, curium oxide and mixtures thereof. ### Claim 23 (depends on 20) The fuel element according to claim 20, wherein said fuel pellets include between about 1 wt. % and about 20 wt. % plutonium oxide and the balance thorium oxide. ### Claim 24 (depends on 20) The fuel element according to claim 20, wherein said fuel pellets are sized to be received within said cladding tube. ### Claim 25 (depends on 20) The fuel element according to claim 20, wherein said inner layer is a monolith layer. ### Claim 26 (depends on 25) The fuel element according to claim 25, wherein said inner monolith layer is formed by chemical vapor deposition. ### Claim 27 (depends on 20) The fuel element according to claim 20, wherein said central layer is a composite of silicon carbide surrounded by a silicon carbide matrix. ### Claim 28 (depends on 27) The fuel element according to claim 27, wherein said central composite layer includes silicon carbide fibers. ### Claim 29 (depends on 28) The fuel element according to claim 28, wherein said silicon carbide fibers are in the form of a tow that includes between about 500 and about 1600 fibers having between about 8 and about 14 microns in diameter. ### Claim 30 (depends on 29) The fuel element according to claim 29, wherein said silicon carbide fibers include a carbon interface coating thickness of between about 0.1 and about 1 micron. ### Claim 31 (depends on 20) The fuel element according to claim 20, further including an outer monolith layer. ### Claim 32 (depends on 31) The fuel element according to claim 31, wherein said outer monolith layer is formed by chemical vapor infiltration or by chemical vapor deposition. ### Claim 33 (depends on 31) The fuel element according to claim 31, wherein said outer monolith layer has a thickness between about 3 and about 10 mils. ### Claim 34 (depends on 20) The fuel element according to claim 20, wherein said multilayer silicon carbide cladding tube is substantially formed of stoichiometric beta silicon carbide crystals that are resistant to damage by neutron radiation. ### Claim 35 (canceled) ### Claim 36 (depends on 20) The fuel element according to claim 20, wherein said end caps are substantially formed of stoichiometric beta silicon carbide crystals that are resistant to damage by neutron radiation. ### Claim 37 (depends on 20) The fuel element according to claim 20, wherein said multilayer silicon carbide cladding tube is between about 1.5 and about 14 feet in length, with a tube wall thickness between about 20 and about 50 mils and with a tube outside diameter between about 0.25 and about 0.5 inches.