DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: On the long-term migration of uranyl in bentonite barrier for high-level radioactive waste repositories: The effect of different host rocks

Abstract

Repositories for high level radioactive waste hosted in argillite or granite with bentonite backfill are the two disposal concepts that been extensively studied. A general perception is that granite has very low sorption capacity and therefore is disadvantageous in retarding the migration of radionuclides in comparison with argillite. However, when there is bentonite backfill, does the sorption capacity of granite really matter for the migration of radionuclides? How different host rocks would affect the migration of U(VI) through the bentonite backfill of an engineered barrier system (EBS), and which properties of the host rocks cause those differences in migration, given that migration of radionuclides is a critical measure in assessing the performance of a repository? Here we present two coupled thermal, hydrological, and chemical models for the transport of U(VI), each with an identical setup except for the type of host rock (argillite vs granite rock). Comparisons between our models show that the different host rocks exert their influence on migration of U(VI) via regulating the chemical conditions in the bentonite, which affect the concentration of U(VI) at the source and the adsorption of U(VI) in the bentonite. The key chemical conditions are pH, Ca+, and HCO3- concentration in pore-water,more » which are strongly affected by soluble carbonate minerals. Our models also show the occurrence of illitization (dissolution of smectite and precipitation of illite) in the bentonite, which affects the migration of U(VI) through changing pH and the quantity of adsorbents. Although generalization of current model results for granite and argillite should be done carefully, the simulations highlight the importance of pore-water chemistry in host rock, as well as bentonite-host rock interactions, when assessing the performance of a repository. In comparison to properties such as thermal conductivity, permeability, and adsorption capacity, properties that have been studied intensively, the pore-water chemistry of host rocks deserve equal or even more attention because of its strong influence on radionuclide migration.« less

Authors:
 [1];  [2];  [1];  [3]
  1. Tsinghua Univ., Beijing (China). School of Environment
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Geosciences Division
  3. Beijing Normal Univ., Beijing (China). College of Water Sciences
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
1559249
Alternate Identifier(s):
OSTI ID: 1543182
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
Chemical Geology
Additional Journal Information:
Journal Volume: 525; Journal Issue: C; Journal ID: ISSN 0009-2541
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES

Citation Formats

Cao, Xiaoyuan, Zheng, Liange, Hou, Deyi, and Hu, Litang. On the long-term migration of uranyl in bentonite barrier for high-level radioactive waste repositories: The effect of different host rocks. United States: N. p., 2019. Web. doi:10.1016/j.chemgeo.2019.07.006.
Cao, Xiaoyuan, Zheng, Liange, Hou, Deyi, & Hu, Litang. On the long-term migration of uranyl in bentonite barrier for high-level radioactive waste repositories: The effect of different host rocks. United States. https://doi.org/10.1016/j.chemgeo.2019.07.006
Cao, Xiaoyuan, Zheng, Liange, Hou, Deyi, and Hu, Litang. Thu . "On the long-term migration of uranyl in bentonite barrier for high-level radioactive waste repositories: The effect of different host rocks". United States. https://doi.org/10.1016/j.chemgeo.2019.07.006. https://www.osti.gov/servlets/purl/1559249.
@article{osti_1559249,
title = {On the long-term migration of uranyl in bentonite barrier for high-level radioactive waste repositories: The effect of different host rocks},
author = {Cao, Xiaoyuan and Zheng, Liange and Hou, Deyi and Hu, Litang},
abstractNote = {Repositories for high level radioactive waste hosted in argillite or granite with bentonite backfill are the two disposal concepts that been extensively studied. A general perception is that granite has very low sorption capacity and therefore is disadvantageous in retarding the migration of radionuclides in comparison with argillite. However, when there is bentonite backfill, does the sorption capacity of granite really matter for the migration of radionuclides? How different host rocks would affect the migration of U(VI) through the bentonite backfill of an engineered barrier system (EBS), and which properties of the host rocks cause those differences in migration, given that migration of radionuclides is a critical measure in assessing the performance of a repository? Here we present two coupled thermal, hydrological, and chemical models for the transport of U(VI), each with an identical setup except for the type of host rock (argillite vs granite rock). Comparisons between our models show that the different host rocks exert their influence on migration of U(VI) via regulating the chemical conditions in the bentonite, which affect the concentration of U(VI) at the source and the adsorption of U(VI) in the bentonite. The key chemical conditions are pH, Ca+, and HCO3- concentration in pore-water, which are strongly affected by soluble carbonate minerals. Our models also show the occurrence of illitization (dissolution of smectite and precipitation of illite) in the bentonite, which affects the migration of U(VI) through changing pH and the quantity of adsorbents. Although generalization of current model results for granite and argillite should be done carefully, the simulations highlight the importance of pore-water chemistry in host rock, as well as bentonite-host rock interactions, when assessing the performance of a repository. In comparison to properties such as thermal conductivity, permeability, and adsorption capacity, properties that have been studied intensively, the pore-water chemistry of host rocks deserve equal or even more attention because of its strong influence on radionuclide migration.},
doi = {10.1016/j.chemgeo.2019.07.006},
journal = {Chemical Geology},
number = C,
volume = 525,
place = {United States},
year = {Thu Jul 04 00:00:00 EDT 2019},
month = {Thu Jul 04 00:00:00 EDT 2019}
}

Journal Article:

Citation Metrics:
Cited by: 8 works
Citation information provided by
Web of Science

Figures / Tables:

Table 1 Table 1: The surface protonation reactions on montmorillonite (smectite) and illite and surface complexation reactions for the sorption of U(VI) on montmorillonite (smectite) and illite

Save / Share:

Works referenced in this record:

Observations and predictions of hydromechanical coupling effects in the Boom clay, Mol Underground Research Laboratory, Belgium
journal, January 2003


How the Kd Approach Undermines Ground Water Cleanup
journal, May 2000


Radionuclide Transport Behavior in a Generic Geological Radioactive Waste Repository
journal, February 2014

  • Bianchi, Marco; Liu, Hui-Hai; Birkholzer, Jens T.
  • Groundwater, Vol. 53, Issue 3
  • DOI: 10.1111/gwat.12171

Towards an understanding of the sorption of U(VI) and Se(IV) on sodium bentonite
journal, December 1998


Sorption modelling on illite Part I: Titration measurements and the sorption of Ni, Co, Eu and Sn
journal, February 2009


Sorption modelling on illite. Part II: Actinide sorption and linear free energy relationships
journal, February 2009


Modelling near- and far-field processes in nuclear waste management
journal, January 2004


Properties, use and health effects of depleted uranium
journal, February 2005


Radionuclide transport model for risk evaluation of high-level radioactive waste in Northwestern China
journal, August 2017

  • Cao, Xiaoyuan; Hu, Litang; Wang, Jinsheng
  • Human and Ecological Risk Assessment: An International Journal, Vol. 23, Issue 8
  • DOI: 10.1080/10807039.2017.1361811

Regional Groundwater Flow Assessment in a Prospective High-Level Radioactive Waste Repository of China
journal, July 2017

  • Cao, Xiaoyuan; Hu, Litang; Wang, Jinsheng
  • Water, Vol. 9, Issue 7
  • DOI: 10.3390/w9070551

Modeling coupled THM processes of geological porous media with multiphase flow: Theory and validation against laboratory and field scale experiments
journal, October 2009


Application of the Surface Complexation Concept to Complex Mineral Assemblages
journal, October 1998

  • Davis, J. A.; Coston, J. A.; Kent, D. B.
  • Environmental Science & Technology, Vol. 32, Issue 19
  • DOI: 10.1021/es980312q

Approaches to surface complexation modeling of Uranium(VI) adsorption on aquifer sediments
journal, September 2004

  • Davis, James A.; Meece, David E.; Kohler, Matthias
  • Geochimica et Cosmochimica Acta, Vol. 68, Issue 18
  • DOI: 10.1016/j.gca.2004.03.003

Intercomparison of reactive transport models applied to UO2 oxidative dissolution and uranium migration
journal, March 2003


Modeling spent nuclear fuel alteration and radionuclide migration in disposal conditions
journal, January 2006


On site measurements of the redox and carbonate system parameters in the low-permeability Opalinus Clay formation at the Mont Terri Rock Laboratory
journal, January 2007

  • Fernández, A. Ma; Turrero, M. J.; Sánchez, D. M.
  • Physics and Chemistry of the Earth, Parts A/B/C, Vol. 32, Issue 1-7
  • DOI: 10.1016/j.pce.2006.02.057

Fabric control on strain and rupture of heterogeneous shale samples by using a non-conventional mechanical test
journal, August 2004

  • Fouché, Olivier; Wright, Hervé; Le Cléac'h, Jean-Michel
  • Applied Clay Science, Vol. 26, Issue 1-4
  • DOI: 10.1016/j.clay.2003.12.014

The effect of calcium on aqueous uranium(VI) speciation and adsorption to ferrihydrite and quartz
journal, March 2006

  • Fox, Patricia M.; Davis, James A.; Zachara, John M.
  • Geochimica et Cosmochimica Acta, Vol. 70, Issue 6
  • DOI: 10.1016/j.gca.2005.11.027

Sorption characteristic of uranium(VI) ion onto K-feldspar
journal, October 2017


A full-scale in situ heating test for high-level nuclear waste disposal: observations, analysis and interpretation
journal, May 2009


Modelling thermo-hydro-mechano-chemical interactions for nuclear waste disposal
journal, May 2010

  • Gens, A.; Guimaräes, L. do N.; Olivella, S.
  • Journal of Rock Mechanics and Geotechnical Engineering, Vol. 2, Issue 2
  • DOI: 10.3724/SP.J.1235.2010.00097

The Grimsel (Switzerland) migration experiment: integrating field experiments, laboratory investigations and modelling
journal, February 1996


Long-term diffusion of U(VI) in bentonite: Dependence on density
journal, January 2017


Characterization of uranium(VI) sorption by organobentonite
journal, June 2010


Estimating the potential for spalling around a deep nuclear waste repository in crystalline rock
journal, February 2009

  • Martin, C. D.; Christiansson, R.
  • International Journal of Rock Mechanics and Mining Sciences, Vol. 46, Issue 2
  • DOI: 10.1016/j.ijrmms.2008.03.001

Kinetics and irreversibility of cesium and uranium sorption onto bentonite colloids in a deep granitic environment
journal, August 2004


Characterization and modeling of diffusion process for mass transport through the Tournemire argillites (Aveyron, France)
journal, August 2004

  • Patriarche, Delphine; Ledoux, Emmanuel; Simon-Coinçon, Régine
  • Applied Clay Science, Vol. 26, Issue 1-4
  • DOI: 10.1016/j.clay.2003.10.005

Study of uranium(VI) and radium(II) sorption at trace level on kaolinite using a multisite ion exchange model
journal, June 2016


Modeling of Coupled Thermo-Hydro-Mechanical Processes with Links to Geochemistry Associated with Bentonite-Backfilled Repository Tunnels in Clay Formations
journal, March 2013

  • Rutqvist, Jonny; Zheng, Liange; Chen, Fei
  • Rock Mechanics and Rock Engineering, Vol. 47, Issue 1
  • DOI: 10.1007/s00603-013-0375-x

THM analysis of a large-scale heating test incorporating material fabric changes
journal, March 2011

  • Sánchez, Marcelo; Gens, Antonio; Olivella, Sebastiá
  • International Journal for Numerical and Analytical Methods in Geomechanics, Vol. 36, Issue 4
  • DOI: 10.1002/nag.1011

Biogenic uraninite precipitation and its reoxidation by iron(III) (hydr)oxides: A reaction modeling approach
journal, August 2011

  • Spycher, Nicolas F.; Issarangkun, Montarat; Stewart, Brandy D.
  • Geochimica et Cosmochimica Acta, Vol. 75, Issue 16
  • DOI: 10.1016/j.gca.2011.05.008

Impact of Uranyl−Calcium−Carbonato Complexes on Uranium(VI) Adsorption to Synthetic and Natural Sediments
journal, February 2010

  • Stewart, Brandy D.; Mayes, Melanie A.; Fendorf, Scott
  • Environmental Science & Technology, Vol. 44, Issue 3
  • DOI: 10.1021/es902194x

Modeling Transport of Cesium in Grimsel Granodiorite With Micrometer Scale Heterogeneities and Dynamic Update of K d : MODELING TRANSPORT OF CESIUM
journal, November 2017

  • Voutilainen, Mikko; Kekäläinen, Pekka; Siitari-Kauppi, Marja
  • Water Resources Research, Vol. 53, Issue 11
  • DOI: 10.1002/2017WR020695

Ten-year results from unsaturated drip tests with UO2 at 90°C: implications for the corrosion of spent nuclear fuel
journal, October 1996


TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions
journal, June 2011


A coupled THMC model of FEBEX mock-up test
journal, January 2008


A coupled THC model of the FEBEX in situ test with bentonite swelling and chemical and thermal osmosis
journal, September 2011