Contact

Porträt Dr. Müller, Katharina; FWOG

Photo: André Wirsig

Dr. Katharina Müller

Head Surface Processes
k.muellerAthzdr.de
Phone: +49 351 260 2439

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Department of Surface Processes

The why? The how? The what?

The ultimate goal of our research, driven by scientific curiosity, is to gain fundamental and independent knowledge of the (geo)chemistry and environmental fate of long-lived radionuclides (RNs). One prominent and socially important application is the safe disposal of radioactive waste, to aid future generations in the responsibility of dealing with “our” legacy from energy production in nuclear reactors.

For this purpose we provide the radiochemical knowledge, namely structural and mechanistic data of important mobilizing and immobilizing reactions of RNs in solution, at interfaces, and in solids.

Our particular focus is using a variety of established and advanced microscopic and spectroscopic techniques, to accurately describe complex formation reactions and complex structures that govern RN interactions in the geosphere. In addition, we investigate the creation and chemical speciation of activation products in materials from nuclear power plants in the context of their safe decommissioning.

As part of a value chain, the derived structural information forms a sound basis for a reliable thermodynamic description of the investigated systems, which can be integrated in thermodynamic databases. The thermodynamic work is done in close collaboration with the department of Actinide thermodynamics.

Foto: Forschungsfelder der Abteilung Grenzflächenprozesse ©Copyright: Dr. Katharina Müller

Our core competencies

  • Chemistry of long-lived RNs – Expertise in handling RNs, ranging from fission- and activation products to transuranium elements, and access to radiation safety labs.
  • Structural characterization – Expertise in applying and coupling spectroscopic and microscopic as well as diffraction techniques for accessing molecular information.
  • Thermodynamic description of RN complexes – Using macroscopic, spectroscopic, and calorimetric information of reactant-water-surface phenomena as basis for the derivation of surface complexation models and their thermodynamic parameters.

Research fields

  • Coordination chemistry of RNs in aqueous solution and in human artificial biofluids, e.g. RADEKOR project.
  • Molecular characterization of RN reactions at natural and engineered mineral-water interfaces, e.g. REDOX project.
  • Incorporation of actinides and lanthanides in solid phases, e.g. AcE project.
  • Environmental technetium chemistry., e.g. Young Investigator Group TecRad.
  • Experimental support for calculations of neutron fields and the resulting activities close to nuclear reactors, e.g. EBENE project.

Latest Publication

Phase composition and stability of Gd2-xThxZrO7 under extreme conditions

Svitlyk, V.; Weiß, S.; Gabarono, G.; Hübner, R.; Worbs, A.; Huittinen, N. M.; Hennig, C.

Abstract

Introduction of Th into a hydrothermally synthesized disordered fluorite-type Gd2Zr2O7 phase induces a transition to an ordered pyrochlore-type phase at a Th concentration of 10% at the Gd site (Gd1.8Th0.2ZrO7 composition). Degree of order of the fluorite-type phase reaches 50% for a Th concentration of 25% (Gd1.5Th0.5ZrO7 composition). Upon application of high pressure, the Gd2Zr2O7 phase retains fluorite-type structure until the pressure of 33 GPa (K0 = 167(1) GPa) where it undergoes a reversible amorphisation. The Gd1.7Th0.3ZrO7 phase was found to be stable until at least the pressure of 25 GPa (K0 = 169(3) GPa). Upon heating to Tmax of 1135 K, the Gd2Zr2O7 phase retains disordered fluorite-type structural arrangement (α = 3.03·10-5 K-1). Excellent stability of the Gd2-xThxZrO7 phases under extreme conditions of temperature and pressure makes Gd2Zr2O7 a promising candidate as a host matrix for radioactive species for safe long-term underground storage of nuclear waste.

Involved research facilities

Related publications

Permalink: https://www.hzdr.de/publications/Publ-38754

More publications

A list of publications can be found here.

Research groups

Currently running third-party funded projects

  • Experimentally supported calculations of neutron fields and the resulting activities in spaces far from the reactor (EBENE) started: 04/2024, BMBF
  • Interactions of technetium with microorganisms, metabolites and at the mineral-water interface – Radioecological considerations (TecRad) started: 07/2022, BMBF
  • Redox reactivity of selenium in environmental geomedia (REDOX) started: 06/2022, ANDRA

An overview of finished projects can be found here.

Team

Foto: Abtei­lung

"Surface processes" department

Head

NameBld./Office+49 351 260Email
Dr. Katharina Müller801/P2482439
k.muellerAthzdr.de

Employees

NameBld./Office+49 351 260Email
Aline Chlupka801/P2033198
2518
2523
a.chlupkaAthzdr.de
Dr. Norbert Jordan801/P2182148
n.jordanAthzdr.de
Stephan Weiß801/P3162758
2523
s.weissAthzdr.de
Maud Emilie Zilbermannm.zilbermannAthzdr.de

Incorporation in solid phases

NameBld./Office+49 351 260Email
Dr. Astrid Barkleit801/P2073136
2512
2518
a.barkleitAthzdr.de

"TecRad" Wechselwirkung von Technetium mit Mikroorganismen, Metaboliten und an Mineral-Wasser-Grenzflächen - Radioökologische Betrachtungen

NameBld./Office+49 351 260Email
Dr. Natalia Mayordomo Herranz801/P2522076
n.mayordomo-herranzAthzdr.de
Caroline Börner801/P2542251
c.boernerAthzdr.de
Arkadz Bureika801/P2012434
a.bureikaAthzdr.de
Irene Cardaio801/P2542251
i.cardaioAthzdr.de
Vijay Kumar Saini801/P3523328
v.sainiAthzdr.de

Alumni

Name at HZDR
Heidrun Neubert Lab assistant
Sara E. Gilson PostDoc
Christa Müller Lab assistant
Quirina Isabella Roode-Gutzmer Ph.D. student
Isabelle Jessat Ph.D. student,
gratuated 2023
Maximilian Demnitz Ph.D. student,
graduated 2022
Diana Marcela Rodriguez Hernandez Ph.D. student,
graduated 2021
Henry Lösch Ph.D. student,
graduated 2021
Manuel Eibl Ph.D. student,
graduated 2020
Susanne Lehmann Ph.D. student,
graduated 2020