Minerals for encapsulation of high-level nuclear waste: simulating damage and durability

放射性废料的处理是核能发电的致命弱点。2001年11月的欧洲晴雨表民意调查显示，如果有确实安全可靠的废物处理方法，大多数欧盟公民会接受核电。然而，自20世纪70年代以来，人们一直关注硼硅酸盐玻璃作为高放废物（HLW）宿主的长期水性耐久性。从大自然中学习，我们一直在使用天然矿物提供的基本见解来指导寻找可以远远超过当前玻璃技术的合成材料，特别是在它们浸入地质废物储存的潜在地下水时，它们在原子尺度结构中保留铀和钚的程度方面。我们的初步工作结合了晶体结构原理的实验工作和计算机模拟。这些突出了在放射性衰变期间发生的对周围晶体的损伤的特征，并表明受损区域在自身周围形成高密度壳。我们建议利用我们最近的进展，了解放射性损伤积累的矿物锆石，使用准确的计算机模拟，测试的假设，锆和钛的氧化物（烧绿石结构）可能是不渗透的和强大的保留放射性核素在地质时间框架。

Radioactive waste disposal is the Achilles heel of nuclear power generation. The Eurobarometer poll of November 2001 revealed a majority of EU citizens would accept nuclear power if an assuredly safe and secure method of waste disposal was available. Yet concerns over the long-term aqueous durability of borosilicate glasses as hosts for high-level waste (HLW) have been noted since the 1970's. Learning from Nature, we have been using the fundamental insights provided by natural minerals to steer the search for synthetic materials that could far outperform the current glass technologies, especially in terms of how well they retain uranium and plutonium within their atomic scale structure when they are immersed in the potential groundwaters of a geological waste store. Our preliminary work has combined experimental work on the principles of crystalline architecture with computer simulations. These highlight the characteristics of damage to the surrounding crystal that occurs during radioactive decay, and show that the damaged regions form high-density shells around themselves. We propose to capitalise on our recent advances in understanding radiation damage accumulation in the mineral zircon, using accurate computer simulations, to test the hypothesis that zirconium and titanium oxides (with the pyrochlore structure) may be as impervious and robust in retaining radionuclides over geological time frames.