| 摘要 |
PROBLEM TO BE SOLVED: To heighten the density of a sintered body of a nuclear fuel by adding a trace of a sintered additive to powdery nuclear fuel manufactured by a wet conversion method, pressing and molding the powdery nuclear fuel and sintering a compact. SOLUTION: One or a mixture of two or more of uranium dioxide, other uranium oxide, plutonium oxide and thorium oxide or a mixture of a neutron absorber such as gadolinium oxide is used as a powdery material for a nuclear fuel. After sulfate or sulfide that functions as a sintered additive is added to a nitric acid solution as a material and is dissolved in it, the powder of uranium dioxide and the like is manufactured by way of ammonium diuranate and carbonic acid uranyl ammonium. The concentration of sulfur in the powder is set at 20 to 40 ppm. The powder is charged into a mold of a molding machine and is molded by the pressure of about 0.5 to 5 ton/cm2 to obtain a compact of 40 to 60% TD. The compact is sintered at the temperature of about 1,500 to 1,800 deg.C for 1 to 10 hours in the atmosphere of hydrogen or a mixed gas of hydrogen and nitrogen and the like or the atmosphere of argon and the like.
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