Description
The characteristics and properties of non-metallic, inorganic waste forms that may be disposed of in a 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.
- 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.
The physical and chemical characteristics of non-metallic inorganic waste forms control the release rates of radioactive and non-radioactive contaminants from these waste forms, and the physical and chemical forms in which they are released. Examples of such waste forms include spent fuel (as UO₂ rather than as a metallic form), concrete and ash. The physical and chemical characteristics and properties of the non-metallic, inorganic materials will also influence how the waste form interacts with any other waste forms (e.g. organics) in the same waste container, and with the waste container itself. Depending upon the physical and chemical characteristics of the non-metallic inorganic waste forms, these latter interactions may influence the rate at which containers degrade. For example, cementitious waste forms may help to buffer conditions within an iron or steel container at high values, thereby minimising the rate of container corrosion.
2000 List
A reference to the related FEP(s) within the 2000 NEA IFEP List.
Related References
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IAEA (), Handling and Processing of Radioactive Waste from Nuclear Applications, IAEA TRS 402, International Atomic Energy Agency, Vienna, http://www-pub.iaea.org/MTCD/Publications/PDF/TRS402_scr.pdf