Impact of self-irradiation damage on the aqueous durability of zircon(ZrSiO4):implications for its suitability as a nuclear waste form
Impact of self-irradiation damage on the aqueous durability of zircon(ZrSiO4):implications for its suitability as a nuclear waste form
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自辐照损伤对锆石（ZrSiO4）水耐久性的影响：对其作为核废料形式的适用性的影响
DOI：
10.1088/0953-8984/15/37/l07
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
E. Salje
中科院分区：
文献类型：
--
作者：
T. Geisler;K. Trachenko;Susana Rı́os;M. Dove;E. Salje
锆石被提议作为一种核废料形式，以安全地封装武器级钚。为了研究锆石中自辐照损伤对其水耐久性的影响，我们用几种自辐照损伤（即非晶化）的锆石样品进行了水热实验（2M CaCl 2溶液，600 °C，100 MPa）。我们发现在两个临界浓度的无定形域的变化率异常增加。当无定形畴在结构中形成相互连接的簇时，第一个显著的增加开始。第二个增加与快速扩散路径的渗透有关，快速扩散路径由在强烈重叠的α反冲事件期间形成的耗尽物质的纳米级区域组成，如分子动力学模拟和小角度X射线散射测量所示。这两个逾渗阈值为锆石废物形式的安全性能提供了模型基准。
Zircon has been proposed as a nuclear waste form to safely encapsulate weapons-grade plutonium. In order to study the impact of self-irradiation damage in zircon on its aqueous durability, we performed a hydrothermal experiment (2 M CaCl2 solution, 600 °C, 100 MPa) with several variably radiation-damaged, i.e. amorphized, zircon samples. We found an anomalous increase in the alteration rate at two critical concentrations of amorphous domains. The first dramatic increase sets in when the amorphous domains form interconnected clusters in the structure. The second increase is related to the percolation of fast diffusion pathways consisting of nano-sized regions of depleted matter that are formed during strongly overlapping α-recoil events, as seen by molecular-dynamics simulations and small-angle x-ray scattering measurements. The two percolation thresholds provide model benchmarks for the safety performance of a zircon waste form.