Next-Generation Low-Carbon Cement Wasteforms for Safe Disposal of Radioactive Waste

在英国，迄今为止已经产生了超过15万立方米的放射性废物（足以填满60个奥运会规模的游泳池）。大多数放射性废物需要用水泥包裹，以防止释放到生物圈中。以波特兰水泥（PC）为基础的包封剂与补充胶凝材料（SCM）（如粉煤灰（FA）和高炉渣（BFS））混合，是迄今为止英国产生的大部分放射性废物的胶结所必需的。然而，随着传统的SCM（如粉煤灰和高炉渣）越来越稀缺，开发利用丰富和现成的SCM（如石灰石、煅烧粘土和遗留渣等）生产的PC/SCM封装剂对于确保供应安全至关重要。目前关于原料参数对可靠应用至关重要的信息有限，特别是当这些封装剂在核封装厂所需的条件下与大量的SCM替代品（如石灰石、煅烧粘土和遗留炉渣）配制时。本研究研究了用石灰石、煅烧粘土和废渣作为BFS和PFA的更丰富替代品生产的PC/SCM封装剂中流体-颗粒和颗粒-颗粒相互作用的机制，以及这种替代品对组成-结构-性能关系、反应机制和动力学的影响。通过研究基本的粒子相互作用，可以利用丰富的scm为前驱体粉末开发更强大的规格，确保供应的安全性。

In the UK, over 150,000m3 of radioactive waste (enough to fill 60 Olympic size swimming pools) has been produced to date. Most of this radioactive waste needs conditioning by encapsulating it in cement to prevent release to the biosphere.Encapsulants based on Portland cement (PC) blended with supplementary cementitious materials (SCM) such as fly ash (FA) and blast furnace slag (BFS) are essential to cementation of much of the radioactive waste produced in the UK to date. However, with traditional SCM such as fly ash and blast furnace slag becoming increasingly scarce, development of PC/SCM encapsulants produced using abundant and readily available SCM such as limestone, calcined clays, and legacy slags, etc., is critical to ensure security of supply.There is currently limited information on what parameters of raw materials are critical to reliable application, particularly when these encapsulants are formulated with abundant SCM alternatives such as limestone, calcined clays, and legacy slags, under conditions required on nuclear encapsulation plants.This proposal investigates the mechanisms of fluid-particle and particle-particle interactions in PC/SCM encapsulants produced using limestone, calcined clays, and legacy slags as more abundant replacements for BFS and PFA,and the effect of this replacement on composition-structure-property relationships, and reaction mechanisms and kinetics.Through investigating fundamental particle interactions more robust specifications can be developed for precursor powders utilising abundant SCMs, ensuring security of supply.