Sorption of palladium(II) on biotite, quartz and feldspar in brackish groundwater by batch experiment, sorption model and DFT calculation

在国际上，像NWMO(核废料管理组织)这样的机构正在考虑在结晶岩或沉积岩地层中建立地下深层地质库，作为处理用过核燃料的安全和长期的解决方案。这些机构将不得不准备一份安全评估，以证明使用过的核燃料将在数十万年内得到安全管理。如果能很好地描述放射性核素在储存库工程屏障和天然屏障中的吸附行为，将提高安全评估的可靠性。在加拿大，NWMO正在与两个潜在的选址区接触，一个在花岗岩中，一个在沉积岩中。在本项目中，将研究Pd(II)在黑云母、石英和长石上的吸附。(Pd-107是一种长寿命的裂变产物，存在于用过的核燃料中，数量可观。石英和长石是花岗岩的主要矿物成分。黑云母是花岗岩中一种常见但次要的矿物成分，被认为是某些放射性核素(如Cs)在花岗岩上的吸附主导。通过将实验与吸附模型和量子化学计算相结合来识别吸附反应，并计算出最优的反应平衡常数。合格的吸附数据将在NWMO的吸附数据库中汇编。这项研究将为加拿大社会带来长期利益，因为它将增强人们对已选择安全地点的信心(确保加拿大人和环境未来的健康和福祉)。该项目将利用麦克马斯特大学在处理痕量放射性核素方面的独特研究能力和专业知识，扩大我们在安全评估中对其中一种核素的吸收过程的科学理解。重要的是，这也将有助于培养使用过的核燃料管理领域的高素质人员。

Internationally, agencies such as the NWMO (Nuclear Waste Management Organization) are considering underground deep geological repositories in either crystalline or sedimentary rock formations as a safe and long-term solution to the disposal of used nuclear fuel. These agencies will have to prepare a safety assessment to demonstrate that used nuclear fuel will be safely managed over hundreds of thousands of years. The reliability of the safety assessment will be improved if the sorption behaviours of radionuclides in the engineered and natural barriers of the repository are well characterized. In Canada, the NWMO is engaging with two potential siting areas, one in granitic rock and one in sedimentary rock. In this project, the sorption of Pd(II) on biotite, quartz and feldspar will be studied. (Pd-107 is a long-lived fission product present in used nuclear fuel in appreciable amounts. Quartz and feldspar are main mineral components of granite. Biotite is a common but minor mineral component of granite and is considered to dominate the sorption of some radionuclides such as Cs on granite.) The sorption reactions will be identified by integrating the experiments with a sorption model and with quantum chemistry calculations, and the optimized equilibrium constants of reactions will be evaluated. Qualified sorption data will be compiled in the sorption database of the NWMO. This study will lead to long-term benefits to Canadian society, as it will allow for increased confidence that a safe site has been selected (ensuring future health and wellbeing of Canadians and the environment). This project will use the unique research capability and expertise at McMaster University for working with trace radionuclides and extend our scientific understanding of sorption processes of one of the nuclides in safety assessment. Importantly, this will also contribute to the development of highly qualified personnel in the fields of used nuclear fuel management.