Dr. Katharina Müller

Head Surface Processes
Phone: +49 351 260 2439

Behavior of long-lived fission and activation products in the near-field of a repository for nuclear waste and possibilities of their retention (VESPA II)

Financed by:
Federal Ministry for Economic Affairs and Energy (02 E 11607B)
Funding period:
2017/09/01 – 2020/08/31
Cooperation Partner:
Karlsruhe Institute for Technology, Institute for Nuclear Waste Disposal (KIT-INE, Karlsruhe, Germany)
Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) GmbH (Braunschweig, Germany)
Institut für Energie- und Klimaforschung Nukleare Entsorgung und Reaktorsicherheit (IEK-6, Jülich, Germany)
N. Mayordomo, D. Rodríguez (PhD student), K. Müller (project leader)
Web page:


Long-term safety assessments for final disposals of high-level radioactive waste have to consider the release of radionuclides from the waste and their potential retention by the multi-barrier system. To date, it has been assumed in long-term safety analysis that there is only retention for cationic but not for anionic species within the near field of final disposals.

In this context, the joint research project VESPA II, has the primary objective to investigate the retention of 79Se, 129I and 99Tc. In aquatic solutions, these elements mainly occur in anionic form and do not form poorly soluble phases. The goals of VESPA II are:

  1. filling the gaps on the reported thermodynamic data related to fission products and
  2. analyzing their retention by minerals phases likely found in the nearfield repository, such as corrosion products.

HZDR is involved in the following work packages

  1. studying the surface speciation and incorporation of Tc(VII) and Tc(IV) on iron corrosion phases, environmental ubiquitous minerals and on LDH phases under reducing conditions and
  2. investigating the Tc chemistry and thermodynamics, especially for low oxidation states.

Bachelor/Master thesis topic


Radiochemistry and the radioactive nuclear waste management

Mayordomo Herranz, N.

  • Invited lecture (Conferences)
    Lectures about chemistry (Lecciones de química), 06.02.2020, Alcalá de Henares, Spain

Technetium retention by gamma alumina nanoparticles and the effect of sorbed Fe²⁺

Mayordomo Herranz, N.; Rodriguez Hernandez, D. M.; Schild, D.; Molodtsov, K.; Johnstone, E. V.; Hübner, R.; Shams Aldin Azzam, S.; Brendler, V.; Müller, K.

New insights into 99Tc(VII) removal by pyrite: A spectroscopic approach

Rodriguez Hernandez, D. M.; Mayordomo Herranz, N.; Scheinost, A.; Schild, D.; Brendler, V.; Müller, K.; Stumpf, T.

⁹⁹Tc immobilization by aluminum solids containing Fe(II) moieties

Mayordomo Herranz, N.; Rodriguez Hernandez, D. M.; Molodtsov, K.; Johnstone, Erik V.; Roßberg, A.; Heim, K.; Foerstendorf, H.; Schild, Dieter; Brendler, V.; Müller, K.

  • Lecture (Conference)
    The 43th symposium on scientific basis for nuclear waste management, 21.-24.10.2019, Viena, Austria

Tc immobilization by Fe(II)-Al(III)-Cl layered double hydroxide phase

Mayordomo Herranz, N.; Rodriguez Hernandez, D. M.; Roßberg, A.; Scheinost, A.; Foerstendorf, H.; Heim, K.; Brendler, V.; Müller, K.

  • Lecture (Conference)
    Gesellschaft Deutscher Chemiker Nuclearchemie 2019, 25.-27.09.2019, Dresden, Germany

⁹⁹Tc retention on Fe(II)Al(III)-Cl layered double hydroxides

Mayordomo Herranz, N.; Rodriguez Hernandez, D. M.; Scheinost, A.; Roßberg, A.; Brendler, V.; Müller, K.

  • Lecture (Conference)
    Goldschmidt 2019, 18.-23.08.2019, Barcelona, Spain

Spectroelectrochemical studies of the Tc(VII) reduction in aqueous electrolyte media

Rodriguez, D.; Mayordomo, N.; Brendler, V.; Müller, K.; Stumpf, T.

  • Poster
    17th international conference on the chemistry and migration behavior of actinides and fission products in the geosphere, 15.-21.09.2019, Kyoto, Japan

Reductive immobilization of 99Tc(VII) by different crystalline phases of iron sulfide (FeS2)

Rodriguez, D.; Mayordomo, N.; Brendler, V.; Müller, K.; Schild, D.; Stumpf, T.

  • Poster
    Migration 2019 - 17th International Conference on the Chemistry and Migration Behavior of Actinides and Fission Products in the Geosphere, 15.-21.09.2019, Kyoto, Japan

99Tc retention on pyrite and alumina: the effect of Fe2+

Rodríguez, D.; Mayordomo, N.; Stumpf, T.; Mueller, K.

  • Lecture (Conference)
    The 10th International Symposium on Technetium and Rhenium – Science and Utilization, 03.-06.10.2018, Moscow, Russia

Environmental fate of fission products: a comprenhensive study

Mayordomo, N.; Rodríguez, D. M.; Müller, K.

  • Invited lecture (Conferences)
    Goldschmidt 2018, 12.-17.08.2018, Boston, USA

Retention of Tc(VII) by pyrite nanoparticles

Rodríguez Hernández, D. M.; Mayordomo-Herranz, N.; Müller, K.

  • Poster
    18th Radiochemical Conference - RadChem 2018, 13.-18.05.2018, Mariánské Lázně, Czech Republic

Tc immobilization on gamma alumina: a study of the reductant presence and absence

Mayordomo, N.; Müller, K.

  • Lecture (Conference)
    18th Radiochemical conference, 13.-18.05.2018, Mariánské Lázně, Czech Republic

KIT      GRS      FZ Jülich      BMWi


Dr. Katharina Müller

Head Surface Processes
Phone: +49 351 260 2439