Description

The migration of dissolved contaminants by the bulk flow of the water through the repository. Included is fluid flow driven by temperature, chemical or electrical gradients, rather than due to hydraulic pressure gradients, called thermal, chemical or electrical osmosis depending on the driving gradient.

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.

Advection of water through the EBS and adjacent geosphere, if it occurs, has the potential to influence the fluxes of radionuclides and other contaminants out of the repository. These radionuclides and other contaminants may originate in the waste, if they are released from a waste package.

If there are also pathways through the surrounding geosphere, via which solutes could be transported from the repository to the biosphere, there could be an impact on the doses of radionuclides and other contaminants received by biosphere receptors.

2000 List

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

3.2.07