RepoTREND - Program package for the integrated long-term safety analysis of repositories

The RepoTREND program package is being developed by GRS to provide a powerful tool for analysing the long-term safety of repositories for radioactive waste.

When modelling the transport of contaminants from the repository to the biosphere, three essentially independent subsystems are considered: the near field, the geosphere and the biosphere. RepoTREND (Transport and REtention of Non-decaying and Decaying contaminants in a REPOsitory) has been designed with a modular structure that reflects this subdivision. It thus provides the capability to model processes occurring in the individual components of the repository system: the potential release of contaminants from the repository, their transport through the geosphere by deep groundwater into near-surface groundwater and ultimately, their transfer to the human organism, together with the associated radiological consequences.

Repository for radioactive waste in deep geological formations
© GRS
Illustration of different exposure pathways with external exposure (Exposure from the outside to the body) and internal exposure (intake of radioactive substances into the human body e.g. via airway or food)

Illustration of different exposure pathways with external exposure (exposure from the outside to the body) and internal exposure (intake of radioactive substances into the human body e.g. via airway or food).

The program package is continuously being further developed and currently comprises the following elements:
 

User interface and control

  • XENIA – graphical user interface for data input and management of computational runs
     

Near field computational module

  • NaTREND – two-phase radionuclide transport in porous media
     

Geosphere computational module

  • POSA – contaminant transport in fully saturated porous media
  • FRAME – contaminant transport in fully saturated fractured porous media considering matrix diffusion
  • COFRAME – colloid-facilitated transport of contaminants in fully saturated fractured-porous media with kinetically controlled interaction processes
  • COFRAME-2 – extension of COFRAME to describe two-site kinetic sorption on colloids
     

Biosphere model

  • BioTREND – calculation of radiation exposure in the biosphere
     

Uncertainty and sensitivity analyses

  • RepoSTAR – framework for probabilistic analyses
     

The individual modules can be flexibly coupled with one another, thereby enabling integrated safety analyses for a wide range of scenarios, repository concepts and host rock formations. RepoTREND is available as open-source software. Its source code, together with additional information, can be found on GitHub.

Computational modules of RepoTREND for different repository compartments
© GRS
RepoTREND