Two-phase transport in a cemented waste package considering spatio-temporal evolution of chemical conditions

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Yonghui Huang - , CAS - Chinese Academy of Sciences, Helmholtz Centre for Environmental Research (Author)
  • Haibing Shao - , Helmholtz Centre for Environmental Research, Freiberg University of Mining and Technology (Author)
  • Erich Wieland - , Paul Scherrer Institute (Author)
  • Olaf Kolditz - , Chair of Applied Environmental Systems Analysis, Helmholtz Centre for Environmental Research (Author)
  • Georg Kosakowski - , Paul Scherrer Institute (Author)

Abstract

The long-term evolution of cemented waste packages is governed by (bio)chemical reactions between waste, cement, and barrier materials, and by transport processes inside the waste package and through openings in the waste package hull. Inside a waste package, gases can be generated by pH-dependent anoxic corrosion of metals and the degradation of organic matter. The (bio)chemical reactions consume water and will not proceed under dry conditions. The degradation of cementitious materials lowers the alkaline pH of the pore water. The modeling of such a complex feedback system shows that the internal structure of a waste package and the exchange of mass with the environment (boundary conditions) are major factors that determine the importance of process couplings. The (bio)chemical reactions are controlled by internal re-distribution of water predominantly via vapor transport. Calculated gas generation rates were found to be affected by dry-out processes inside the drum.

Details

Original languageEnglish
Article number4
Journalnpj Materials Degradation
Volume5
Issue number1
Publication statusPublished - Dec 2021
Peer-reviewedYes