Description

Movement of lithospheric plates (which comprise the Earth’s outermost layer) due to convection cells in the underlying mantle. These movements give rise to large-scale processes such as continental drift, mountain building (orogeny), crustal deformation (including basin formation), faulting, folding and subduction. They typically occur over periods of millions of years.

Category

Categorisation as a Feature, Event and/or Process.

  • Features are physical components of the disposal system and environment being assessed. Examples include waste packaging, backfill, surface soils. Features typically interact with one another via processes and in some cases events.
  • Events are dynamic interactions among features that occur over time periods that are short compared to the safety assessment timeframe such as a gas explosion or meteorite impact.
  • "Processes" are issues or dynamic interactions among features that generally occur over a significant proportion of the safety assessment timeframe and may occur over the whole of this timeframe. Events and processes may be coupled to one another (i.e. may influence one another).

The classification of a FEP as an event or process depends upon the assessment context, because the classification is undertaken with reference to an assessment timeframe. In this generic IFEP List, many IFEPs are classified as both Events and Processes; users will need to decide which of these classifications is relevant to their context and its timeframes.

  • Process

Comments

The “Comments” field, when present, contains any additional explanation of the IFEP, beyond that implicit in the FEP's description and provided in the “Relevance to Performance and Safety” field. This additional explanation may include, where appropriate, the IFEPs characteristics, the circumstances under which it might be relevant and its relationship to other (especially similar) IFEPs.

Short-term effects of tectonic movement (this FEP, 1.2.1) are covered by Seismicity (FEP 1.2.4), Magmatic and volcanic activity (FEP 1.2.5) and Deformation (elastic, plastic, or brittle) (FEP 1.2.3)

Relevance to Performance and Safety

The “Relevance to Performance and Safety” field contains an explanation of how the IFEP might influence the performance and safety of the disposal system under consideration through its impact on the evolution of the repository system and on the release, migration and/or uptake of repository-derived contaminants.

Movements of the lithospheric plates into which the solid outer layer of the earth is divided affect both regional and local processes of safety relevance to a repository. The general environmental characteristics of the repository environment (e.g. distance from the ocean, elevation above sea level, climatic conditions) will be influenced strongly by tectonic movements. For example, mountain building (FEP 1.2.2) due to these movements may influence atmospheric circulation and local rainfall. The frequency, magnitude and proximity to a repository of seismic events (FEP 1.2.4) will depend upon the location of the repository relative to the deformation caused by tectonic movements. The spatial distribution, magnitude and characteristics of magmatic activity (FEP 1.2.4), including volcanism, are influenced by tectonic movements. Tectonic movement may alter the separation between a repository and the biosphere during the post-closure period. Weathering and erosion (FEP 1.2.5) accompanying uplift may cause the repository to approach the ground surface. Conversely, sedimentation that may accompany subsidence (FEP 1.2.5) would cause the repository to be buried at greater depths below the ground surface. Deformation due to tectonic movements (FEP 1.2.3) has the potential to create or seal pathways via which water or gas may transport radionuclides and other contaminants from a repository. Such deformation may lead to a displacement of waste packages, damage to engineered barriers or damage to the geosphere barrier. For example, active faulting (FEP 1.2.3 and FEP 1.2.4) due to tectonic movements may generate transmissive fracture pathways. Tectonic deformation may also influence the forces that could drive fluid flow through the repository, for example by influencing water pressures and pressure gradients. Thermal gradients within the geosphere surrounding the repository may also be influenced by tectonic movements, owing to these movements causing uplift and subsidence, influencing the locations and characteristics of magmatism and influencing fluid flow.

2000 List

A reference to the related FEP(s) within the 2000 NEA IFEP List.

1.2.01

Related References

  • IAEA (), Scientific and Technical Basis for the Geological Disposal of Radioactive Wastes, IAEA Technical Report Series, International Atomic Energy Agency, Vienna, 413, 80, http://www-pub.iaea.org/MTCD/publications/PDF/TRS413_web.pdf
  • Connor C B, Chapman N A and Connor L J (), Volcanic and Tectonic Hazard Assessment for Nuclear Facilities, Cambridge University Press, ISBN 978-0-521-88797-7 hardback