| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of controlling a concentration at which an additive agent is solved at a crystal grain boundary in sintering of a uranium-based oxide compact which varies in solid solution concentration in uranium-based oxide according to oxygen partial pressure of sintering gas, and contains an additive agent element, and to provide a method of manufacturing a nuclear fuel sintered body which has large crystal grains. <P>SOLUTION: There is provided a crystal grain boundary solid solution concentration adjustment method for a heterogenous additive element which keeps a crystal grain boundary solid solution concentration of the heterogeneous additive agent element at a certain level during sintering of the uranium-based oxide compact containing additive agent powder of a heterogenous element by changing the oxygen partial pressure in stages during isothermal sintering when the uranium-based oxide compact is sintered. Further, there is provided a method of manufacturing a nuclear fuel sintered body which has large crystal grains including a stage of preparing mixed uranium oxide powder of the additive agent, a stage of forming a mixed uranium oxide compact of the additive agent using the mixture, a heating stage of raising temperature of the compact to the sintering temperature of the compact under a gas atmosphere of low oxygen partial pressure, and a stage of sintering the compact by changing a sintering gas atmosphere so as to raise the oxygen partial pressure in stages at the isothermal sintering temperature. <P>COPYRIGHT: (C)2012,JPO&INPIT |
