Korea Atomic Energy Research Institute

Korea Hydro Nuclear Power Co., Ltd.

Other

Korea Electric Power Corporation

Keon-Sik Kim

Jong-Hun Kim

Jae-Ho Yang

Dong-Joo Kim

Kun-Woo Song

Yang-Hyun Koo

Young Woo Rhee

JangSoo Oh

Youn-Ho Jung

Ki-Won Kang

Young-Woo Rhee

Dong Seok Kim

Myung-Seung Yang

Chill-Sun Ryu

Jae-Jo Yang

Disclosed are a nuclear fuel pellet having enhanced thermal conductivity and a method of manufacturing the same, the method including (a) a step of manufacturing a mixture including a nuclear fuel oxide powder and a thermally conductive plate-shaped metal powder; and (b) a step of molding and then heat-treating the thermally conductive plate-shaped metal powder to have an orientation in a horizontal direction in the mixture, thereby forming a pellet.

Nuclear fuel pellet having enhanced thermal conductivity and method of manufacturing the same

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

Provided are a method of controlling the compositional gradient and solubility of doped-additives at grain boundaries during sintering of a uranium-based oxide green pellet including the additives, and a method of manufacturing a sintered nuclear fuel pellet having a large grain size using the same. The grain boundary solubility of the doped-additives is maintained at a certain level by stepwise varying of an oxygen partial pressure during isothermal sintering of a uranium-based oxide green pellet including the additives. The method of manufacturing a sintered nuclear fuel pellet having a large grain size includes preparing additive mixed uranium oxide powder, forming an additive mixed uranium oxide green pellet using the mixed powder, heating the green pellet to a sintering temperature in a gas atmosphere having a low oxygen partial pressure, and sintering while a sintering gas atmosphere is changed to stepwise increase an oxygen partial pressure at the isothermal sintering temperature.

Method of controlling solubility of additives at and near grain boundaries, and method of manufacturing sintered nuclear fuel pellet having large grain size using the same

A method for fabricating a sintered annular nuclear fuel pellet includes molding nuclear fuel powder or granule, an oxide of a fissile element (M), to fabricate an annular nuclear fuel green body. A rod-like shaped structure is inserted into the annular nuclear fuel green body and sintered in a slight oxidizing gas atmosphere such that the oxide of the fissile element has a balanced O/M ratio higher than a desired O/M ratio (oxygen/fissile element) of a final sintered annular nuclear fuel pellet, while being maintained in a cubic phase. The sintered annular nuclear fuel pellet is then reduced in a reductive gas atmosphere so as to have the desired O/M ratio in the state that the rod-like shaped structure is inserted.

Method for preparing sintered annular nuclear fuel pellet

A method for fabricating a sintered annular nuclear fuel pellet includes: molding nuclear fuel powder or granules to fabricate an annular nuclear fuel green body; inserting a rod-like shaped structure into the annular nuclear fuel green body; sintering the rod-like shaped structure-inserted annular nuclear fuel green body in a reductive gas atmosphere; and separating the sintered annular nuclear fuel pellet from the rod-like shaped structure.

Method for fabricating sintered annular nuclear fuel pellet through rod-inserted sintering

The present invention relates to a method for measuring the content of Lanthanides dissolved in uranium oxide, wherein the Lanthanides content in the nuclear fuel pellet is measured using the thermo gravimetric analysis which measures the weight variation caused by the oxidation and heat treatment of the nuclear fuel pellet. This method provides an advantage in that the Lanthanide content can be measured using relatively simple equipments such as an electric furnace and a balance.

Method for measuring lanthanide content dissolved in uranium oxide

A method of manufacturing new UO,-based fuel pellets by recycling irradiated UO,-based fuel pellets. Irradiated UO,-based fuel pellets are oxidized so as to make U,O,-based powder, and then the U,O,-based powder is mixed with an additive which contains at least one oxide of an element selected from the group consisting of niobium, titanium, vanadium, aluminum, magnesium, chromium, silicon and lithium. Green pellets are formed from the mixed powder, and then sintered, preferably at 1500&deg; C. or higher, in a reducing gas atmosphere to produce UO,-based fuel pellets with high densities.

Method of manufacturing a nuclear fuel pellet by recycling an irradiated oxide fuel pellet

A method is disclosed in which fuel scrap of UO.sub.2 alone or UO.sub.2 containing an oxide of plutonium, gadolinium or erbium is recycled into the manufacture of nuclear fuel pellets. The fuel scrap consisting of defective fuel pellets is comminuted through oxidation to fuel particles of U.sub.3 O.sub.8 alone or U.sub.3 O.sub.8 containing an oxide of plutonium, gadolinium or erbium, and a sintering aid containing an element selected from the group consisting of aluminum, magnesium, niobium, titanium, vanadium, chromium, lithium, silicon, tin and mixtures thereof is added in a quantity of about 0.02% to about 2% by weight to the sintering powder which consists of said recycled fuel particles and fresh fuel powder having a composition of UO.sub.2 alone or UO.sub.2 in a mixture of PuO.sub.2, Gd.sub.2 O.sub.3 or Er.sub.2 O.sub.3. The sintering powder is then mixed uniformly, in which the amount of the recycled fuel particles is in the range of about 10% to about 100% by weight. Green pellets are made by pressing the sintering powder and then sintered at about 1500.degree. C. to about 1800.degree. C. in a reducing atmosphere to produce new fuel pellets.

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Daejeon, South Korea

Keon-Sik Kim