Description

The characteristics of weather and climate, and the processes affecting their potential evolution.

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

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.

Climate and weather are characterised by precipitation, temperature, pressure and wind speed and direction. Accounting for variability in these characteristics, extreme events such as drought, flooding, storms and snow melt are identified. In addition to long-term variations (FEPs 1.3.1 and 1.3.2), daily and seasonal variations can have a wide influence. For example, these variations affect irrigation requirements for agricultural crops, habitat for animal populations and the source of drinking water.

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.

Climate and weather will determine the availability and quality of surface water resources, and thus the demands of the local community on potential contaminated near-surface aquifers to extract water for irrigation, bathing and ingestion. Climatic conditions will also influence the nature of the crops that can grow. Climate and weather may influence other behaviours of both humans and non-human biota, such as time spent outdoors, and even diet. All these factors will influence the migration of and exposure to any repository-derived contaminants that might reach the biosphere.

2000 List

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

2.3.10

Related References

  • IAEA (), Environmental Change in Post-closure Safety Assessment of Solid Radioactive Waste Repositories, Working Group 3 Reference Models for Waste Disposal of EMRAS II Topical Heading Reference Approaches for Human Dose Assessment. Environmental Modelling for Radiation Safety (EMRAS II) Programme, International Atomic Energy Agency, Vienna, IAEA-TECDOC-1799, http://www-pub.iaea.org/MTCD/Publications/PDF/TE1799web.pdf