Sinterability of ZrN and (ZrDy)N pellets; Surrogate fuel fabrication for ELECTRA

ZrNと(ZrDy)Nペレットの焼結性; ELECTRAの燃料製造の模擬試験

Pukari, M.*; 高野 公秀 

Pukari, M.*; Takano, Masahide

窒化物燃料ペレットの不活性母材成分のZrNと、燃料模擬物質として(ZrDy)Nを調製し、調製過程における酸素及び炭素不純物の増加要因と焼結性への影響を調べた。含有酸素濃度を、2種の異なる方法で人為的に1.5wt%まで高め、成型後及び焼結後のペレット密度を酸素濃度,粉末比表面積,温度の関数として定めた。さらに、酸素の存在形態に関して、窒化物中への固溶と酸化物としての相分離の2種類を比較検討した。調製中の各過程及び調製後の窒化物中の不純物と相は、窒素,酸素,炭素の定量分析とX線回折、及びSEM/EDXによる分析で詳細に評価した。

Pellets of inert matrix material ZrN and surrogate nitride fuel material (ZrDy)N are fabricated for the purpose of investigating the origin and the effect of C and O impurity concentrations. Oxygen concentrations of up to 1.5 wt% were deliberately introduced to the materials with two separate methods. The achievable green and sintered pellet densities of these materials as a function of O content, dimensional properties of the powder and sintering temperature are shown. The effect of O dissolved into the matrix vs oxide-rich phase segregation is discussed. Oxygen pickup during the fabrication of the product as well as its exposure to air is demonstrated. The quality of the materials is monitored by the systematic analysis of O, N and C contents throughout the fabrication and sintering processes, supported by XRD and SEM analyses.