Short-term irradiation behavior of low-density americium-doped uranium-plutonium mixed oxide fuels irradiated in a fast reactor

アメリシウム含有する高速炉用低密度燃料の短期照射挙動

前田 宏治  ; 勝山 幸三 ; 生澤 佳久   ; 前田 誠一郎 

Maeda, Koji; Katsuyama, Kozo; Ikusawa, Yoshihisa; Maeda, Seiichiro

Amを含有する低密度燃料の熱的挙動を把握するため、短期・高線出力照射試験(B14)を高速実験炉「常陽」において実施した。照射試験パラメータとして、燃料O/M比及び燃料-被覆管ギャップ幅を設定し、4本の燃料ピンを装荷した。燃料ピンは48時間のプレコンディショニングにより組織変化させた後、最大線出力470W/cmまで急昇させて10分間保持された。照射後に破壊試験により燃料溶融が生じていないことや、PuやAmの再分布について調査した。本破壊試験結果は、これまでに取得したデータと比較して熱的性能を検討した。

In order to evaluate the thermal behavior of low-density uranium and plutonium mixed oxide fuels containing several percent of americium (Am-MOX), fuel irradiation test (B14) was conducted using the experimental fast reactor. Pellet-cladding gap width and O/M ratio of oxide fuels were specified as experimental parameters. Four fuel pins were irradiated step-by-step in consideration of fuel restructuring during 48 hours as pre-conditioning before full power reactor operation. The irradiation history, i.e. linear power, was simulated the conventional FBR oxide fuel pins. And the linear power was rapidly increased up to 47 kW/cm for 10 minutes to simulate the transient condition. After the irradiation, ceramography samples were taken from the axial position of each fuel pins where the fuel centerline temperature reached the maximum during irradiation. The result was investigated relative to those of other irradiated fuels.