Reference N° Creation Date SCK CEN/39400143 2020-12-14 Alternative Reference N° Revision Version N/A 1.0 2 ISC Revision Status Restricted Approved Master thesis UHasselt - Niels Palmans - Adsorption_desorption_behaviour_of_CO2_and_H2O_on_ThO2_powders - 2019-2020.pdf Authors* Rémi Delville Approval information for current revision* Name Outcome Date Marc Verwerft Approved 2021-02-22 Change log* Revision Version Status Date Description of change 1.0 2 Approved 2020-12-14 *This automatically generated cover page shows references and workflow status information as were available in the Alexandria document management system on 2021-02-22. Please refer to Alexandria for current and complete metadata, or to the document contents and/or author for additional information. Confidentiality statement The information contained in this document is only for the information of the intended recipient. It may not be used, modified, published or redistributed without the prior explicit written consent of SCK CEN. In all circumstances, SCK CEN staff and external workers shall handle this document in accordance with the policies and security controls described in the 'information protection policy' (197-POL-001). Deze masterproef werd geschreven tijdens de COVID-19 crisis in 2020. Deze wereldwijde gezondheidscrisis heeft mogelijk een impact gehad op de opdracht, de onderzoekshandelingen en de onderzoeksresultaten. SCK CEN/39400143 Rev. 1.0 I SCK CEN/39400143 Rev. 1.0 II Acknowledgments Firstly, I would like to thank SCK CEN for allowing me to do research with such advanced measurement equipment. The team of scientists that was active in lab 46, where the largest majority of the practical work was performed, went out of their way to make sure I had always access to the necessary equipment, which was greatly appreciated. Subsequently, many people made a significant contribution to this thesis, without whom this work would not have been possible. Most notably, I would like to thank my external promotor Dr. Beatriz Acevedo Muñoz, who provided the main guidance and was the most closely involved in the research subject. As time was of the essence, she provided a detailed day-by-day planning for me to structure the experimental work. Furthermore, she provided me with an abundance of literature sources to aid me in my literature review and get me worked in in the subject. She was always ready to assist me in any practical work and showed great patience when some clumsiness got the better of me. Even when the planning took a heavy blow after the Corona measures were set in place, she performed a multitude of experiments in my place, assuring experimental data for all samples. Without her, there would have been no experimental data of the 2-step alkali precipitated thoria powder. Additionally, she took the time to provide me with important advice and remarks concerning the dissertation which raised the overall quality to a higher standard. Being grateful would therefore be an understatement. Furthermore, I am very grateful for the guidance Dr. Rémi Delville provided for me. He made sure regular reality checks were performed during my time at SCK CEN so that I did not get overwhelmed and stayed focussed on the right tasks. Additionally, his remarks on the dissertation during the writing process taught me an invaluable lesson about efficiency, focus, and relevancy. I would also like to thank Prof. Dr. Sonja Schreurs, who provided important insight into the general structure of the thesis and valuable remarks on the subjects discussed. Her advice also allowed me to greatly improve the quality of the thesis by addressing some key issues in my early writing style. Next, I would like to thank Dr. Marc Verwerft for helping me keeping a structured approach to my work amidst pandemic chaos. Weekly progress reports made sure I kept track of my progress while planning new tasks ahead of time and spreading the workload evenly. I also greatly appreciate the assistance I received from Koen Vanaken and Peter Dries in the lab environment. When I had any questions or doubts during my time working in the nuclear labs, Koen and Peter would often be present to assist me whenever necessary. Koen also provided me with a detailed explanation about the practical safety guidelines within the lab so that I would always be working safely with the equipment. In general, I would like to thank the other members of the FMA group for making my rather limited time at SCK CEN a very pleasant experience. The work environment was very welcoming and I felt at home quickly. On a more personal note, I would like to thank my family for the perpetual moral support. I would also like to thank my closest friends, Marijn Roothooft, Vincenth Willems and Mattias Simons for their incredible support and encouragement during the COVID-19 quarantine (and subsequently the social isolation). Regular electronic meet-ups assured I stayed focussed and motivated throughout this difficult time. SCK CEN/39400143 Rev. 1.0 III SCK CEN/39400143 Rev. 1.0 IV Influence of COVID-19 pandemic The research described in this thesis work was performed during the 2020 COVID-19 pandemic. As measures imposed by the Belgian government were tightened, I was no longer legally allowed to continue performing experiments at SCK CEN myself due to the abrupt suspension of internships starting on the 16th of March. Therefore, the experimental planning was interrupted and some compromises had to be made. Most notably, as the access to the labs was limited, repetitions of experiments with some questionable results were difficult and the overall amount of experiments had to be scaled down. The latter mostly affected the ThO_TSA experiments as only three different adsorption times mere measured once. Furthermore, seeing how the cycle of reuse of a sample influenced the adsorption capacity, I would have liked to repeat a few experiments with a freshly calcined oxalate sample. However, this was not feasible knowing the time such an experiment takes. Additionally, as internships were suspended, my external promotor Beatriz Acevedo Muñoz performed some of the experimental work in my place. To keep the workload in check, the number of experiments was decreased. Additionally, the workflow was severely interrupted due to organisational difficulties following the sudden necessity of electronic media for communication. That being said, I firmly believe this research has a valid role to play in the study of adsorption of atmospheric gases to thoria powders. SCK CEN/39400143 Rev. 1.0 V SCK CEN/39400143 Rev. 1.0 VI Table of Contents List of Tables ......................................................................................................................................IX List of figures .....................................................................................................................................XI Abstract (EN) ................................................................................................................................... XIII Abstract (NL) .................................................................................................................................... XV 1. Introduction .............................................................................................................................. 17 1.1 A brief history .................................................................................................................... 17 1.2 Benefits of thorium-based fuel .......................................................................................... 18 1.3 Problem statement ............................................................................................................ 20 2. Objectives ................................................................................................................................. 23 3. Theoretical background ............................................................................................................. 25 3.1 Thorium fuel cycle ............................................................................................................. 25 3.2 Thorium-based fuel manufacturing: the front-end fuel cycle ............................................. 26 3.2.1 Mining ....................................................................................................................... 27 3.2.2 Purification ................................................................................................................ 27 3.2.3 Enrichment ................................................................................................................ 28 3.2.4 Pellet fabrication........................................................................................................ 28 3.2.5 Scrap recycling and bundle assembly ......................................................................... 29 3.3 Adsorption theory ............................................................................................................. 29 3.3.1 Fundamentals of adsorption theory ........................................................................... 30 3.3.2 Derivation of Henry’s and Freundlichs adsorption isotherm ....................................... 32 3.3.3 The Langmuir adsorption isotherm ............................................................................ 33 3.4 Applications for adsorption techniques.............................................................................. 34 3.4.1 The use of adsorption