Description

The changes in sea level which may occur as a result of global climatic change and regional geological change, e.g. isostatic movements. The component of sea level change involving the interchange of water between land ice and the sea is referred to as eustatic change. As ice sheets melt so the ocean volume increases and sea levels rise. Sea level at a given location will also be affected by vertical movement of the land mass, e.g. depression and rebound due to glacial loading and unloading, referred to as isostatic change.

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.

Sea-level change could impact upon the performance and safety of a repository that is sufficiently close to the coast by: 1) influencing the fluxes and patterns of groundwater flow in and/or around a repository; 2) influencing the chemistry of the groundwater in and/or around the repository; and 3) influencing the nature and spatial distribution of receptors that could be impacted by any radionuclides or contaminants that are transported from the repository. The first influence arises because sea level change could affect the groundwater flow regime around a repository, which could influence the transport of radionuclides and other contaminants from a repository to the locations of groundwater discharge. Sea-level change could also influence the rates and spatial distribution of erosion or sediment deposition, which could affect the depth of the repository below the surface in the long term. These erosion/sedimentation processes and the presence/absence of a column of seawater above a repository have the potential to influence mechanical loading of the repository.

2000 List

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

1.3.03

Related References