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

A. Gens, M. Sanchez, L.D.N. Guimarães, E.E. Alonso, A. Lloret, S. Olivella, M.V. Villar, F. Huertas

Research output: Contribution to journalArticle

93 Citations (Scopus)

Abstract

The paper describes the performance, observations and interpretation of a large-scale in situ heating test that simulates a disposal concept for heat-emitting, high-level nuclear waste. In the experiment, heaters are emplaced in the axis of a tunnel excavated in granite to simulate the heat production of radioactive waste. The test is fully instrumented, and attention is focused on the thermo-hydro-mechanical (THM) behaviour of the near-field region constituted by the compacted bentonite barrier surrounding the heater and the immediately adjacent rock. Interpretation of the test is assisted by the performance of a coupled numerical analysis based on a formulation that incorporates the relevant THM phenomena. Initial and boundary conditions for the analysis as well as material parameters are determined from an extensive programme of field and laboratory experiments. The paper presents and discusses the thermal, hydraulic and mechanical observations in the bentonite barrier and in the host rock. Special attention is paid to the progress of hydration in the barrier, to the effects of heating and vapour transport, and to the development of swelling pressures in the barrier. After five years of heating, one of the heaters was switched off and the experiment was partially dismantled, allowing the final state of the barrier to be observed directly. The numerical analysis performed has proved able to represent the progress of the experiment very satisfactorily. In addition, predictions concerning the final state of the clay barrier are very close to the observations obtained during dismantling. The performance and analysis of the in situ test have significantly enhanced the understanding of a complex THM problem and have proved the capability of the numerical formulation to provide adequate predictive capacity.
LanguageEnglish
Pages377-399
Number of pages22
JournalGeotechnique
Volume59
Issue number4
DOIs
Publication statusPublished - 2009

Fingerprint

Radioactive wastes
Waste disposal
waste disposal
radioactive waste
heating
Heating
Bentonite
bentonite
Numerical analysis
Experiments
Rocks
heat production
in situ test
experiment
Granite
hydration
Hydration
swelling
host rock
Swelling

Keywords

  • expansive soils
  • full-scale tests
  • numerical modelling
  • partial saturation
  • temperature effects

Cite this

Gens, A., Sanchez, M., Guimarães, L. D. N., Alonso, E. E., Lloret, A., Olivella, S., ... Huertas, F. (2009). A full-scale in situ heating test for high-level nuclear waste disposal: observations, analysis and interpretation. Geotechnique, 59(4), 377-399. https://doi.org/10.1680/geot.2009.59.4.377
Gens, A. ; Sanchez, M. ; Guimarães, L.D.N. ; Alonso, E.E. ; Lloret, A. ; Olivella, S. ; Villar, M.V. ; Huertas, F. / A full-scale in situ heating test for high-level nuclear waste disposal: observations, analysis and interpretation. In: Geotechnique. 2009 ; Vol. 59, No. 4. pp. 377-399.
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Gens, A, Sanchez, M, Guimarães, LDN, Alonso, EE, Lloret, A, Olivella, S, Villar, MV & Huertas, F 2009, 'A full-scale in situ heating test for high-level nuclear waste disposal: observations, analysis and interpretation' Geotechnique, vol. 59, no. 4, pp. 377-399. https://doi.org/10.1680/geot.2009.59.4.377

A full-scale in situ heating test for high-level nuclear waste disposal: observations, analysis and interpretation. / Gens, A.; Sanchez, M.; Guimarães, L.D.N.; Alonso, E.E.; Lloret, A.; Olivella, S.; Villar, M.V.; Huertas, F.

In: Geotechnique, Vol. 59, No. 4, 2009, p. 377-399.

Research output: Contribution to journalArticle

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AU - Sanchez, M.

AU - Guimarães, L.D.N.

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AU - Olivella, S.

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AU - Huertas, F.

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KW - expansive soils

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KW - numerical modelling

KW - partial saturation

KW - temperature effects

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