1. Diploma: Master of sciences (Chemistry)
2. Profile:
Knowledge of solvent extraction and separation chemistry is a plus
Good skills in performing chemical experiments
Ability to work in an interdisciplinary and collaborative environment
Ability to write clear scientific reports and disseminate results
Good oral, interpersonal and written communication skills
Creative and self-motivated
Committed to achieve objectives and overcoming obstacles
Committed to safe working and operational procedures
Generation IV reactors are being developed to enhance the efficiency and sustainability of nuclear electricity production. SCK CEN is involved in the development of Lead-Cooled Fast Reactors (LFRs) which use liquid lead or lead-bismuth eutectic as coolant. This coolant enables high-temperature operation without pressurization and offers an enhanced neutron economy leading to a better fuel utilization. A current trend is the development of Small Modular Reactors (SMRs), which are safer, more flexible, and scalable. The EAGLES consortium, including SCK CEN, is working on LEANDREA, an SMR-LFR demonstrator planned for 2035 in Mol. It will use MOX fuel with high plutonium content (30% PuO₂). A swift recovery of plutonium and uranium from spent SMR-LFR fuel and recycling into new fuel is essential as plutonium is a synthetic element. The high Pu content presents some challenges for the aqueous reprocessing of spent FR MOX fuel of which the most important are slow dissolution in nitric acid, increased insoluble Pu containing residues, radiolysis of solvents, criticality risks. Furthermore, SCK CEN has performed experiments in the 1980s on fast reactor MOX fuels e.g. the FARFADET experiments which aimed to study the fuel restructuring, cladding corrosion and thermal behavior at the beginning of life. Due to the termination of the fast reactor program, the post-irradiation examination (PIE) was, however, never completed. The fuel from these experiments remains stored at SCK CEN and currently no disposal strategy exists. In the context of LEANDRA and to reduce waste liability for historical fuels, the back-end of the nuclear fuel cycle for these high Pu containing MOX fuels will be studied. A nitric acid dissolution method for the MOX fuel will be developed. Since MOX fuels with high Pu content are difficult to dissolve, development of an electrochemically assisted or ultrasonic aided dissolution method might be needed. For the recycling of Pu and U from used fuel, the PUREX process is the most widely used and industrially mature method. The aim of the PhD study is to develop a CHON compliant separation process. The degradation products will interfere less with the separation process and during the second-generation MOX fuel fabrication they will be burned off during calcination and/or sintering stages and will not affect the purity of the recycled U and/or Pu product.
The student will develop advanced dissolution methods for difficult-to-dissolve MOX fuels and develop a CHON compliant solvent extraction process for recycling of Pu and U from historical and future high Pu MOX fuels. Radiochemical analysis and measurement uncertainty analysis will be performed by the student as well as UV/Vis spectroscopy, pycnometry and microscopy.
The research activities will be carried out in the Radiochemistry (RCA) expert group of the Belgian Nuclear Research Center (SCK CEN) in Mol, Belgium. The Radiochemistry expert group investigates the chemical and radiochemical composition of different types of nuclear materials. Their analytical services play a key role in many research projects at SCK CEN and are also offered to external clients. Via continuous R&D, radiochemical analytical methods are developed to anticipate future analytical needs. In addition to their analysis activities, they develop innovative radiochemical processes for the production of radio-isotopes, the partitioning of minor actinides and the production of nuclear fuels and transmutation targets.More information on the Radiochemistry expert group can be found on the following website: https://www.sckcen.be/en/expertises/nuclear-lifecycle/radiochemistry The student will be affiliated to the Arenberg Doctoral School of KU Leuven (Belgium). The PhD thesis will be supervised by Prof. Koen Binnemans, professor of metallurgical chemistry and head of the SOLVOMET group: https://chem.kuleuven.be/solvomet 4 year PhD position funded by the SCK CEN. The student will also be affiliated to the KU Leuven (Belgium). This PhD project concerns a collaboration between SCK CEN and KU Leuven. The student will carry out all the experimental work in the radiochemical laboratories of the SCK CEN in Mol (Belgium).