AcE: Fundamental investigations of Actinide immobilization by incorporation into solid phasEs relevant for final disposal

AcE: Grundlegende Untersuchungen zur Immobilisierung von Actiniden mittels Einbau in endlagerrelevante Festphasen

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Finanaced by: German Federal Ministry of Education and Research (BMBF)

Funding period: 01.01.2021 – 31.12.2023

Grant number: 02NUK060

About the project

The AcE project aims to understand the incorporation and immobilization of actinides (An) in crystalline, repository-relevant solid phases at the atomic level. Investigated solid materials include various Zr(IV)-bearing phases such as zircon (ZrSiO₄), zirconia (ZrO₂), and pyrochlore (Ln₂Zr₂O₇), as well as structurally related UO₂-based materials with fluorite structure, and lanthanide (Ln-)orthophosphates of the monazite type (LnPO₄). These solid phases are of relevance in the corrosion of the Zircaloy cladding surrounding spent nuclear fuels rods, or they are envisioned as ceramic hosts for the immobilization and safe disposal of specific actinide-bearing waste streams generated in the late stages of the nuclear fuel cycle. Furthermore, UO₂-based materials will be investigated in the context of spent nuclear fuel final disposal of which such materials form a key component of.

The main objectives of the AcE project are (i) the development of synthesis strategies for primarily An(IV)-doped solid phases, (ii) understanding their associated structural and physical properties using combined atomistic and experimental approaches and (iii) determining their performance after irradiation with particular regard to assessment of their long-term stability, dissolution behavior, and suitability for An matrix incorporation.

Novel approaches to improve the safe management of radioactive waste will be explored during the course of this project, which will contribute to the evaluation of innovative disposal strategies and extend the knowledge regarding the fate of actinides during long-term disposal in underground repositories.

Finally, an important aspect of the project is to contribute to the maintenance and extension of expertise and in-depth understanding of radionuclide immobilization in the field of radioactive waste management by educating and supporting pre- and postgraduate students and early career scientists.

Project partners

	Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology Dr. Nina Huittinen (project coordination) Dr. Christoph Hennig Dr. Volodymyr Svitlyk M.Sc. Luiza Braga Ferreira dos Santos
	Rheinisch–Westfälische Technische Hochschule Aachen University Institute of Crystallography Priv.-Doz. Dr. Lars Peters (vice coordinator) M.Sc. Theresa Lender
	Rheinisch–Westfälische Technische Hochschule Aachen University Institute of Mineral Engineering Dr. Thorsten Tonnesen M.Sc. Jonas Nießen
	Forschungszentrum Jülich Nuclear Waste Management and Reactor Safety Dr. Gabriel Murphy
	Goethe-Universität Frankfurt Institute of Geosciences Prof. Bjoern Winkler Dr. Julien Marquardt

Publications

Peer-reviewed journal articles

2024

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2023

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2022

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Theses

• Selina Richter (2022) “Synthesis and Characterization of Lanthanide and Actinide Zirconates”, Bachelor thesis, Technische Universität Dresden
• Lucas Opitz (2021) "Interactions of Ln (Ce, Eu, Gd) and Cm with ZrO(OH)₂ and their incorporation into m ZrO₂", Master’s thesis, Technische Universität Dresden

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