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Improvement on Coupling Technique Between COMSOL and PHREEQC for the Reactive Transport Simulation

  • Received : 2022.08.05
  • Accepted : 2022.10.24
  • Published : 2023.03.31

Abstract

APro, a modularized process-based total system performance assessment framework, was developed at the Korea Atomic Energy Research Institute (KAERI) to simulate radionuclide transport considering coupled thermal-hydraulic-mechanical-chemical processes occurring in a geological disposal system. For reactive transport simulation considering geochemical reactions, COMSOL and PHREEQC are coupled with MATLAB in APro using an operator splitting scheme. Conventionally, coupling is performed within a MATLAB interface so that COMSOL stops the calculation to deliver the solution to PHREEQC and restarts to continue the simulation after receiving the solution from PHREEQC at every time step. This is inefficient when the solution is frequently interchanged because restarting the simulation in COMSOL requires an unnecessary setup process. To overcome this issue, a coupling scheme that calls PHREEQC inside COMSOL was developed. In this technique, PHREEQC is called through the "MATLAB function" feature, and PHREEQC results are updated using the COMSOL "Pointwise Constraint" feature. For the one-dimensional advection-reaction-dispersion problem, the proposed coupling technique was verified by comparison with the conventional coupling technique, and it improved the computation time for all test cases. Specifically, the more frequent the link between COMSOL and PHREEQC, the more pronounced was the performance improvement using the proposed technique.

Keywords

Acknowledgement

This work was supported by the Institute for Korea Spent Nuclear Fuel (iKSNF) and National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Science and ICT, MSIT) (NRF-2021M2E1A1085185).

References

  1. J.W. Kim, H. Jang, D.H. Lee, H.H. Cho, J. Lee, M. Kim, and H. Ju, "A Modularized Numerical Framework for the Process-based Total System Performance Assessment of Geological Disposal Systems", Nucl. Eng. Technol., 54(8), 2828-2839 (2022). https://doi.org/10.1016/j.net.2022.02.018
  2. COMSOL AB, COMSOL Multiphysics Reference Manual, Version: COMSOL 5.5, Stockholm, Sweden (2021).
  3. S.R. Charlton and D.L. Parkhurst, "Modules Based on the Geochemical Model, PHREEQC for use in Scripting and Programming Languages", Comput. Geosci., 37(10), 1653-1663 (2011). https://doi.org/10.1016/j.cageo.2011.02.005
  4. A. Nardi, A. Idiart, P. Trinchero, L.M. de Vries, and J. Molinero, "Interface COMSOL-PHREEQC (iCP), an Efficient Numerical Framework for the Solution of Coupled Multiphysics and Geochemistry", Comput. Geosci., 69, 10-21 (2014). https://doi.org/10.1016/j.cageo.2014.04.011
  5. L. Wissmeier and D.A. Barry, "Simulation Tool for Variably Saturated Flow With Comprehensive Geochemical Reactions in two- and Three-Dimensional Domains", Environ. Model. Softw., 26(2), 210-218 (2011). https://doi.org/10.1016/j.envsoft.2010.07.005
  6. S.C. Seetharam and D. Jacques, "Developments in a Coupled Thermal-Hydraulic-Chemical-Geomechanical Model for Soil and Concrete", Proc. of the COMSOL Conference in Rotterdam 2013, October 23-25, 2013, Rotterdam.
  7. O. Nasir, M. Fall, and E. Evgin, "A Simulator for Modeling of Porosity and Permeability Changes in Near Field Sedimentary Host Rocks for Nuclear Waste Under Climate Change Influences", Tunn. Undergr. Space Technol., 42, 122-135 (2014). https://doi.org/10.1016/j.tust.2014.02.010
  8. S. Ogata, H. Yasuhara, N. Kinoshita, and K. Kishida, "Coupled Thermal-Hydraulic-Mechanical-Chemical Modeling for Permeability Evolution of Rocks Through Fracture Generation and Subsequent Sealing", Comput. Geosci., 24(5), 1845-1864 (2020). https://doi.org/10.1007/s10596-020-09948-3
  9. C.I. Steefel and K.T.B. MacQuarrie, "Approaches to Modeling of Reactive Transport in Porous Media", Rev. Mineral. Geochem., 34(1), 85-129 (1996).
  10. D.L. Parkhurst and C.A.J. Appelo. January 23 2013. "Description of Input and Examples for PHREEQC Version 3-A Computer Program for Speciation, BatchReaction, one-Dimensional Transport, and Inverse Geochemical Calculations." U.S. Geological Survey Techniques and Methods 6-A43. Accessed Aug. 3 2022. Available from: http://pubs.usgs.gov/tm/06/a43.