Description
The damage caused to the waste package by radiation.
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.
- 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.
Radiation damage
refers to changes in the structure of a material due to the action of particles produced by either fission, or radioactive decay, or by recoil of atoms within the structure that undergo decay. The most important structural changes occur due to the loss of energy by particles produced by decay or fission during elastic collisions with atoms in the material, and by recoil of atoms produced by decay. Electronic excitation of atoms by beta particles and alpha particles, and formation of new elements by radioactive decay (transmutation) may also cause radiation damage. This damage can change the macro-physical properties of the material (e.g. embrittlement). The damage can also influence the mass transport properties of the materials. The rate at which radionuclides are released from a waste form will depend partly upon the degree of radiation damage to the waste form.
2000 List
A reference to the related FEP(s) within the 2000 NEA IFEP List.
Related References
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Jenčič I (), Radiation damage in nuclear waste materials, International Conference Nuclear Energy in Central Europe 2000. Golf Hotel, Bled, Slovenia,, http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/34/087/34087571.pdf , 10 September 2000