论文标题
在蒸汽腐蚀期间
Structural and phase evolution in U$_3$Si$_2$ during steam corrosion
论文作者
论文摘要
u $ _3 $ si $ _2 $核燃料在氘化的蒸汽中腐蚀，并具有原位中子衍射。密度功能理论与氢化物的严格热力学描述相结合，包括气体/固体熵贡献。 h在2 $ b $ u $ _3 $ si $ _2 $ h $ _x $的2 $ b $的间隙网站中吸收，并移至8 $ j $ for $ x \ ge ge 0.5 $。水合力量扩展和$ A/C $比率的变化与现场偏好有关。 Rietveld改进跟踪350-500°C的腐蚀反应，并偏爱8J位点。在375°C以上，UO $ _2 $，U $ _3 $ SI $ _5 $和USI $ _3 $的形成发生在晶界和散装中。水合发生在大量中，并在其他反应之前进行。
U$_3$Si$_2$ nuclear fuel is corroded in deuterated steam with in situ neutron diffraction. Density functional theory is coupled with rigorous thermodynamic description of the hydride including gas/solid entropy contributions. H absorbs in the 2$b$ interstitial site of U$_3$Si$_2$H$_x$ and moves to 8$j$ for $x\ge 0.5$. Hydriding forces lattice expansion and change in $a/c$ ratio linked to site preference. Rietveld refinement tracks the corrosion reactions at 350-500 °C and preference for the 8j site. Above 375 °C, formation of UO$_2$, U$_3$Si$_5$ and USi$_3$ take place in the grain boundaries and bulk. Hydriding occurs in bulk and precedes other reactions.
