Description

The human activities that could affect the change of climate either globally or in a region. This FEP covers global warming due to man-made emissions of “greenhouse gases" such as CO₂ and CH₄. It also covers more local variations, for example micro-climates due to urban development.

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.

Human influences on climate could impact upon repository performance and safety 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; 3) influencing the processes by which radionuclides or other contaminants that originate in a repository may be concentrated or dispersed in near-surface environments; and 4) influencing the nature and spatial distribution of receptors that could be impacted by any radionuclides or contaminants that are transported from the repository. Human influences on climate could operate either globally, as in the case of global warming due to emissions of greenhouse gases (principally CO₂ and CH₄) or locally (e.g. in the case of micro-climates being developed around large cities). Over the timescale of a typical performance assessment, anthropogenic effects could result in changes to air temperatures and the quantity and nature of precipitation (i.e. whether rain or snow). The human influences on climate would be superimposed on natural climatic influences, resulting in modified temporal changes in conditions throughout the timeframe of a safety assessment. The groundwater flow regime in and /or around a repository could be modified by changes in the geographical distribution and rate of recharge, caused in turn by anthropogenic climatic effects. Changes in the flow regime could influence the transport of radionuclides and other contaminants from the repository to the locations of groundwater discharge. Modifications to recharge could also lead to variations in the chemical conditions in and / or around the repository (e.g. higher recharge leading to fresh, oxidising, meteoric water penetrating to greater depth). Changes in temperature and/or the magnitude and kind of precipitation (i.e. rain or snow) and / or deglaciation or glaciation could also influence the rates of erosion or sediment deposition. These processes could in turn affect the depth of the repository below the surface in the long term. Changes in erosion/sedimentation and development/drying out of surface water bodies (i.e. lakes) all have the potential to influence mechanical loading of a repository. Climatic effects caused by human activity could include changes to processes that might influence the concentration or dispersion of radionuclides and other contaminants in near-surface environments, such as drainage patterns and erosion rates.

2000 List

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

1.4.01

Related References