Description

The processes related to migration of contaminants within the geosphere in the aqueous phase (including dissolved gases).

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.

  • Event
  • Process

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.

Water-mediated migration may influence the rates at which radionuclides and other contaminants are transported through the geosphere from a repository and the pathways follows (if release of radionuclides and other contaminants through the EBS is possible). Such migration will affect the potential for the biosphere to be exposed to these radionuclides and other contaminants, and the doses of radionuclides and other contaminants received by biosphere receptors. The nature of the receptors and the doses will depend in part on the orientations of the migration pathways, the groundwater fluxes attained, hydrodynamic dispersion, and partitioning of radionuclides and other contaminants between the water and solid and gaseous phases.

2000 List

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

3.2.07