The feasibility of modelling coupled processes in safety analysis of spent nuclear fuel disposal

Kari Rasilainen, Ari Luukkonen, Auli Niemi, Markus Olin, Jukka Pöllä

Research output: Book/ReportReport

Abstract

The potential of applying coupled modelling in the Finnish safety analysis programme has been reviewed. The study focused on the migration of radionuclides escaping from a spent fuel repository planned to be excavated in fractured bedrock. Two effects that can trigger various couplings in and around a spent fuel repository in Finland were studied in detail; namely heat generation in the spent fuel and the presence of deep, saline groundwaters. The latter have been observed in coastal areas. A systematic survey of the requirements of coupled modelling identified features that render such migration calculations a challenging task. In groundwater flow modelling there appears to be wide ranging uncertainty related to conceptualisation of flow systems and to the corresponding input data. In terms of migration related chemistry there appear to be large gaps in the underlying thermodynamic database for geochemical systems. Rock mechanical predictions are heavily dependent on knowing the location, structure and properties of dominant fractures; information which is extremely difficult to obtain. Conduction and convection of heat is understood well in principle. On the basis of this review, it appears that coupled migration modelling may not yet be at the stage of development that would allow its use as a standard modelling tool in performance assessments. However, a firmer basis for the conclusions reached can only be obtained after a systematic modelling exercise on a relevant and real migration problem has been carried out.
Original languageEnglish
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Number of pages87
ISBN (Electronic)951-38-5465-5
ISBN (Print)951-38-5464-7
Publication statusPublished - 1999
MoE publication typeD4 Published development or research report or study

Publication series

SeriesVTT Tiedotteita - Meddelanden - Research Notes
Number1973
ISSN1235-0605

Fingerprint

modeling
repository
flow modeling
performance assessment
groundwater flow
radionuclide
bedrock
thermodynamics
convection
safety analysis
nuclear fuel
groundwater
prediction
rock
analysis programme
coastal area
effect
calculation

Keywords

  • nuclear fuels
  • spent fuels
  • waste management
  • repositories
  • safety analysis
  • modelling
  • feasibility studies
  • ground water
  • fluid flow
  • radionuclide migration

Cite this

Rasilainen, K., Luukkonen, A., Niemi, A., Olin, M., & Pöllä, J. (1999). The feasibility of modelling coupled processes in safety analysis of spent nuclear fuel disposal. Espoo: VTT Technical Research Centre of Finland. VTT Tiedotteita - Meddelanden - Research Notes, No. 1973
Rasilainen, Kari ; Luukkonen, Ari ; Niemi, Auli ; Olin, Markus ; Pöllä, Jukka. / The feasibility of modelling coupled processes in safety analysis of spent nuclear fuel disposal. Espoo : VTT Technical Research Centre of Finland, 1999. 87 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1973).
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abstract = "The potential of applying coupled modelling in the Finnish safety analysis programme has been reviewed. The study focused on the migration of radionuclides escaping from a spent fuel repository planned to be excavated in fractured bedrock. Two effects that can trigger various couplings in and around a spent fuel repository in Finland were studied in detail; namely heat generation in the spent fuel and the presence of deep, saline groundwaters. The latter have been observed in coastal areas. A systematic survey of the requirements of coupled modelling identified features that render such migration calculations a challenging task. In groundwater flow modelling there appears to be wide ranging uncertainty related to conceptualisation of flow systems and to the corresponding input data. In terms of migration related chemistry there appear to be large gaps in the underlying thermodynamic database for geochemical systems. Rock mechanical predictions are heavily dependent on knowing the location, structure and properties of dominant fractures; information which is extremely difficult to obtain. Conduction and convection of heat is understood well in principle. On the basis of this review, it appears that coupled migration modelling may not yet be at the stage of development that would allow its use as a standard modelling tool in performance assessments. However, a firmer basis for the conclusions reached can only be obtained after a systematic modelling exercise on a relevant and real migration problem has been carried out.",
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Rasilainen, K, Luukkonen, A, Niemi, A, Olin, M & Pöllä, J 1999, The feasibility of modelling coupled processes in safety analysis of spent nuclear fuel disposal. VTT Tiedotteita - Meddelanden - Research Notes, no. 1973, VTT Technical Research Centre of Finland, Espoo.

The feasibility of modelling coupled processes in safety analysis of spent nuclear fuel disposal. / Rasilainen, Kari; Luukkonen, Ari; Niemi, Auli; Olin, Markus; Pöllä, Jukka.

Espoo : VTT Technical Research Centre of Finland, 1999. 87 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1973).

Research output: Book/ReportReport

TY - BOOK

T1 - The feasibility of modelling coupled processes in safety analysis of spent nuclear fuel disposal

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AU - Niemi, Auli

AU - Olin, Markus

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N2 - The potential of applying coupled modelling in the Finnish safety analysis programme has been reviewed. The study focused on the migration of radionuclides escaping from a spent fuel repository planned to be excavated in fractured bedrock. Two effects that can trigger various couplings in and around a spent fuel repository in Finland were studied in detail; namely heat generation in the spent fuel and the presence of deep, saline groundwaters. The latter have been observed in coastal areas. A systematic survey of the requirements of coupled modelling identified features that render such migration calculations a challenging task. In groundwater flow modelling there appears to be wide ranging uncertainty related to conceptualisation of flow systems and to the corresponding input data. In terms of migration related chemistry there appear to be large gaps in the underlying thermodynamic database for geochemical systems. Rock mechanical predictions are heavily dependent on knowing the location, structure and properties of dominant fractures; information which is extremely difficult to obtain. Conduction and convection of heat is understood well in principle. On the basis of this review, it appears that coupled migration modelling may not yet be at the stage of development that would allow its use as a standard modelling tool in performance assessments. However, a firmer basis for the conclusions reached can only be obtained after a systematic modelling exercise on a relevant and real migration problem has been carried out.

AB - The potential of applying coupled modelling in the Finnish safety analysis programme has been reviewed. The study focused on the migration of radionuclides escaping from a spent fuel repository planned to be excavated in fractured bedrock. Two effects that can trigger various couplings in and around a spent fuel repository in Finland were studied in detail; namely heat generation in the spent fuel and the presence of deep, saline groundwaters. The latter have been observed in coastal areas. A systematic survey of the requirements of coupled modelling identified features that render such migration calculations a challenging task. In groundwater flow modelling there appears to be wide ranging uncertainty related to conceptualisation of flow systems and to the corresponding input data. In terms of migration related chemistry there appear to be large gaps in the underlying thermodynamic database for geochemical systems. Rock mechanical predictions are heavily dependent on knowing the location, structure and properties of dominant fractures; information which is extremely difficult to obtain. Conduction and convection of heat is understood well in principle. On the basis of this review, it appears that coupled migration modelling may not yet be at the stage of development that would allow its use as a standard modelling tool in performance assessments. However, a firmer basis for the conclusions reached can only be obtained after a systematic modelling exercise on a relevant and real migration problem has been carried out.

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ER -

Rasilainen K, Luukkonen A, Niemi A, Olin M, Pöllä J. The feasibility of modelling coupled processes in safety analysis of spent nuclear fuel disposal. Espoo: VTT Technical Research Centre of Finland, 1999. 87 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1973).