Patent Number: 
Section: claims

1. A method of preparing a nuclear fuel pellet comprising a thermal conductive metal network, the method comprising:preparing an oxide nuclear fuel granule having about 30% to about 45% theoretical density (T.D.);mixing the prepared oxide nuclear fuel granule with a thermal conductive metal powdercompacting the oxide nuclear fuel granule with which the thermal conductive metal powder is mixed to prepare a green pellet; andsintering the green pellet prepared. 2. The method as set forth in claim 1, wherein the oxide nuclear fuel comprises at least one kind of metal oxide nuclear fuels selected from the consisting of UO2, PuO2, and ThO2. 3. The method as set forth in claim 1, wherein the thermal conductive metal powder comprises at least one kind of metals selected from the group consisting of molybdenum (Mo), tungsten (W), and chromium (Cr). 4. The method as set forth in claim 1, wherein the thermal conductive metal powder is mixed at a ratio of about 5 volume % to 15 volume % with respect to the oxide nuclear fuel granule. 5. The method as set forth in claim 1, wherein the thermal conductive metal powder has a size of about 10 μm or less. 6. The method as set forth in claim 1, wherein the green pellet is prepared at a compaction pressure of about 100 MPa to about 500 MPa. 7. The method as set forth in claim 1, wherein the sintering is performed under a hydrogen gas atmosphere. 8. The method as set forth in claim 1, wherein the sintering is performed at a temperature of about 1,300° C. to 1,800° C. for about 1 hour to about 10 hours. 9. The method as set forth in claim 1, the nuclear fuel pellet comprises a thermal conductive metal having a network structure. 10. The method as set forth in claim 1, wherein the nuclear fuel pellet has a density that is greater than about 96% theoretical density (T.D). 11. The method as set forth in claim 9, wherein the thermal conductive metal having the network structure is distributed in at least one nuclear fuel pellet. 12. A method of improving thermal conductivity of a nuclear fuel pellet, the method comprising:mixing an oxide nuclear fuel granule having about 30% to about 45% theoretical density (T.D.) with thermal conductive metal powder;compacting the oxide nuclear fuel granule with which the thermal conductive metal powder is mixed to prepare a green pellet; andsintering the green pellet,wherein a network structure of a thermal conductive metal is formed in the pellet. 13. The method as set forth in claim 1, wherein the prepared oxide nuclear fuel granule has a size of about 200 μm to about 1,000 μm. 14. The method as set forth in claim 12, wherein the prepared oxide nuclear fuel granule has a size of about 200 μm to about 1,000 μm.