Korea Atomic Energy Research Institute

Korea Hydro Nuclear Power Co., Ltd.

Young Woo Rhee

Jong-Hun Kim

Jong Hun Kim

Keon-Sik Kim

Kun Woo Song

Dong-Joo Kim

Yang-Hyun Koo

Jae Ho Yang

Keon Sik Kim

Ki Won Kang

Jae-Ho Yang

JangSoo Oh

Youn Ho Jung

Jae-Jo Yang

Dong Joo Kim

A method of a nuclear fuel pellet including a thermal conductive metal and a nuclear fuel pellet prepared thereby. The method includes preparing an oxide nuclear fuel granule having about 30%-45% theoretical density, mixing the fuel granule with thermal conductive metal powder, compacting the fuel granule with which the thermal conductive metal powder is mixed to prepare a green pellet, and sintering the green pellet. In the method, the sintering may be performed under a reducing gas atmosphere that is the same as the commercial pellet preparing process. Thus, compatibility compared to existing commercial preparing processes may be superior. Also, since a liquefied oxide formation process and a reducing process are omitted, the distribution uniformity of the metal material within the pellet may be superior. Therefore, the nuclear fuel pellet in which the metal network and fine microstructure are uniformly distributed within the pellet may be prepared.

Method of preparing nuclear fuel pellet including thermal conductive metal and nuclear fuel pellet prepared thereby

A uranium dioxide nuclear fuel pellet has about 50 to about 400 &#x3bc;M (with respect to a 3-dimentional size) microcells formed of a ceramic material having a chemical attraction with fission products generated in the nuclear fuel pellet to absorb and trap the fission products, such that the extraction of the fission product may be retrained in a normal operation condition and that the performance of the nuclear fuel may be enhanced by mitigating PCI. In addition, highly radioactive fission products including Cs and I having a large generation amount or a long half-life enough to affect the environments can be trapped in the pellet in an accident condition, without being released outside.

Uranium dioxide nuclear fuel pellet having ceramic microcells

Disclosed is a uranium dioxide nuclear fuel pellet, which includes metallic microcell partitions having a high protection capacity for fission products and a high thermal conductivity simultaneously. These metal microcell partitions are arranged in the nuclear fuel pellet to trap fission products. Further disclosed is a method of making the uranium dioxide nuclear fuel pellet. The method includes providing a mixture of uranium dioxide powder and additive powder of Cr-containing compound or Mo-containing compound; compressing the powder mixture to form a green pellet; and then sintering the green pellet under reducing gas environment to form the metallic microcell partitions.

Uranium dioxide nuclear fuel pellet having metallic microcells and fabricating method thereof

A fabrication method of burnable absorber nuclear fuel pellets and burnable absorber nuclear fuel pellets fabricated by the same are provided, in which the fabrication method includes adding boron compound and manganese compound to one or more type of nuclear fuel powders selected from the group consisting of uranium dioxide (UO), plutonium dioxide (PuO) and thorium dioxide (ThO) and mixing the same (step 1), compacting the mixed powder of step 1 into compacts (step 2), and sintering the compacts of step 2 under hydrogen atmosphere (step 3). According to the fabrication method, sintering can be performed under hydrogen atmosphere at a temperature lower than the hydrogen atmosphere sintering that is conventionally applied in the nuclear fuel sintered pellet mass production, by adding sintering additives such as manganese oxide or the like.

Fabrication method of burnable absorber nuclear fuel pellets and burnable absorber nuclear fuel pellets fabricated by the same

UOnuclear fuel pellets are fabricated by adding additive powder comprising Mn compound and Al compound into UOpowder.

Uranium dioxide nuclear fuel containing Mn and Al as additives and method of fabricating the same

There is provided a method of producing UOpowder having large surface area and small particle size by oxidizing defective UOpellets and manufacturing nuclear fuel pellets which are stable in a pore structure and high in density through the use of a mixture comprising UOpowder and UOpowder. The method includes producing an U308 powder having a surface area of at least 1 m/g by oxidizing defective UOpellets at a temperature of 300 to 370&#xb0; C. in such a way that a maximum weight increase rate per 1 g of the UOpellets is up to 0.06 wt %/min; producing a mixed powder by mixing the UOpowder with an UOpowder by 2 to 15 wt %; producing a compact by compression molding the mixed powder; and sintering the compact in a reducing gas atmosphere at a temperature of 1600 to 1800&#xb0; C. In addition, a small amount of an Al-compound may be added to the oxidized UOpowder before the UOpowder is mixed with the UOpowder. The additive such as Al is mixed with the UOpowder and then mixed with the UOpowder to produce the pellets by a conventional production method. This ensures a stable pore structure, high density and a considerable increase in a crystal grain size.

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A method for manufacturing an annular nuclear fuel pellet is provided. In the method, an annular nuclear fuel green compact whose lateral cross-section is a trapezoid is prepared. The thickness of the annular nuclear fuel green compact reduces along one direction of the central axis, and a green density of the nuclear fuel green compact increases along one direction of the central axis. The annular nuclear fuel green compact is sintered under a reducing gas atmosphere so that the annular nuclear fuel pellet is obtained. According to this method, the annular pellet which has uniform inner and outer diameters and small diametric tolerances along the pellet height is fabricated without grinding the pellet surfaces.

Method for manufacturing sintered annular nuclear fuel pellet without surface grinding

A method for fabricating a sintered duplex nuclear fuel pellet includes the steps of: preparing a first powder composed of a material selected from the group consisting of UOand UO&#x2014;ErO, and a second powder composed of UO&#x2014;GdOand a sintering additive; producing a duplex compact consisting of an annular outer portion composed of the first powder and a cylindrical inner portion composed of the second powder; and sintering the duplex compact under a reducing gas atmosphere, wherein the sintering additive contains manganese of 0.001% to 2% by weight based on the total weight of the cylindrical inner portion.

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Daejeon, South Korea

Young Woo Rhee