Description
The resources within the geosphere, particularly those that might encourage investigation or excavation at or near the repository site. Included are natural resources such as oil, gas, solid minerals, water and geothermal resources. Can also include the presence of suitable rocks for the storage of gases by humans for subsequent use (e.g. natural gas) or sequestration (e.g. carbon dioxide). In this case, the natural porosity within a rock formation may be considered a resource.
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.
- Feature
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.
Geological resources near a repository may provide an incentive for people to undertake disruptive activities in or near the repository following repository closure. Such activities might include borehole drilling or mining, extraction of groundwater or other fluids (gas, liquid hydrocarbons), and storage or disposal of materials such as carbon dioxide. Potentially, these activities could compromise the effectiveness of the geosphere barrier around the repository, by creating new pathways for the migration of fluids transporting radionuclides and other contaminants that originate in the repository, or by disturbing existing pathways by which fluids (such as liquid water, non-aqueous liquids or gases) may flow.
If the repository itself is intruded or impacted directly by nearby activities (e.g. cyclical groundwater pressure changes due to storage and extraction of natural gas), the effectiveness of the EBS could be impacted.
Certain kinds of resource, such as potable groundwater or natural gas, could directly transport radionuclides or other contaminants originating in the repository through the geosphere.
2000 List
A reference to the related FEP(s) within the 2000 NEA IFEP List.