Description
The biological/biochemical processes that affect the host rock and other rock units, and the overall biological/biochemical evolution of the geosphere. Included are the effects of changes in conditions, e.g. on microbe populations, due to the long-term presence of the repository.
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.
Biological processes in the geosphere during repository construction, during repository operation, and later, post-closure, may influence the effectiveness of the EBS and the geosphere barrier. Many of the chemical reactions that may influence chemical conditions in the geosphere, and consequently in the repository, are mediated by micro-organisms. Microbes that enter the repository (e.g. carried by inflowing groundwater) may participate in chemical reactions by which the EBS evolves (e.g. microbiologically influenced corrosion). Should the EBS system have pathways for mass transport between the repository and the geosphere, micro-organisms could potentially participate in the release of radionuclides and other contaminants from wastes and could influence the forms in which such releases occur. For example, micro-organisms could participate in breaking down organic waste forms. By influencing chemical conditions biological processes in the geosphere may impact upon partitioning of radionuclides and other contaminants between mobile fluid phases and immobile solid phases.
2000 List
A reference to the related FEP(s) within the 2000 NEA IFEP List.