Description
The biological/biochemical processes that affect the waste packages.
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.
Potentially, biological/biochemical processes could impact upon all aspects of a waste package’s chemical evolution and consequently the physical characteristics of waste package components (since chemical and physical processes are coupled). Formation of biofilms could also affect the mass transport properties of materials composing a waste package. Biological / biochemical processes may therefore influence the release rates of radionuclides or other contaminants from the waste form. The chemical and physical forms in which such releases occur may be affected by the biological /biochemical processes. Biological / biochemical processes may also influence the nature of the phases that are present within the waste package at any time. For example, the rates of gas generation, and the gas composition, could be controlled by biological processes. Thus, the pressure evolution, and the pressures attained within the waste package, could also be influenced by biological / biochemical processes. This pressure evolution potentially may influence the integrity of the waste package. If the waste package does not offer full containment (either because it is vented or because it has been breached), the pressure evolution could affect the transport of radionuclides and other contaminants from the waste package. These biological / biochemical processes may affect the characteristics of engineered components, and potentially their performance. For example, microbes may influence corrosion of metals (‘microbially -influenced corrosion’).
2000 List
A reference to the related FEP(s) within the 2000 NEA IFEP List.
Related References
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Liengen T, Basseguy R, Feron D and Beech I (), Understanding Biocorrosion, Fundamentals and Applications. 1st Edition, Woodhead Publishing, ISBN 9781782421207, https://www.elsevier.com/books/understanding-biocorrosion/liengen/978-1-78242-120-7