Assessment of different conditioning cementitious matrices for the immobilization of organic waste.
Thesis title:
Assessment of different conditioning cementitious matrices for the immobilization of radioactive organic waste.
Summary of the thesis topic:
Radioactive liquid organic waste (RLOW), generated from various nuclear activities, poses significant challenges for safe conditioning and disposal. This type of waste includes mineral oils, alkanes, motor oils, and tributyl phosphate (TBP). Ordinary Portland cement (OPC), commonly used for the immobilisation of radioactive waste, is often ineffective for encapsulating organic liquid waste due to the low retention of organic compounds within the matrix and the deterioration of the resulting waste form properties.
The objective of this research is to evaluate the immobilisation of representative organic liquid wastes using alternative cementitious matrices. The lubricating oil simulant representative of RLOW will be conditioned in three different matrices: a reference OPC matrix, a Blended Cement Material (BCM), and an Alkali-Activated Material (AAM).This research is suitable for up to 2 students.
The study will focus on the formulation development and optimisation of these matrices and on evaluating the resulting waste forms with respect to the Belgian nuclear waste acceptance criteria. Experimental investigations will include fresh-state properties, such as workability, setting time, and hydration kinetics, as well as hardened-state properties, including mechanical strength, dimensional stability, and mass evolution under aggressive environmental conditions, such as water immersion and exposure to high temperature and relative humidity. Accelerated leaching tests will be performed on samples doped with cesium nitrate. In addition, microstructural and mineralogical analyses using SEM-EDS, XRD, and TGA will be conducted to improve the understanding of the reaction mechanisms and oil encapsulation processes.
Required student background:
Master's degree in Civil Engineering, Materials Engineering, Chemical Engineering, Nuclear Engineering, or a related engineering discipline. Interest in materials science, experimental research, and nuclear waste management.