Description
The sequence of events and activities occurring during repository construction, operation and closure. Relevant events may include phased excavation of emplacement rooms and emplacement of wastes, backfilling, sealing and closure of sections of the repository after wastes are emplaced and monitoring activities.
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
Comments
The “Comments” field, when present, contains any additional explanation of the IFEP, beyond that implicit in the FEP's description and provided in the “Relevance to Performance and Safety” field. This additional explanation may include, where appropriate, the IFEPs characteristics, the circumstances under which it might be relevant and its relationship to other (especially similar) IFEPs.
Schedule and planning (this FEP, 1.1.4) covers the planning and sequencing of Construction (FEP 1.1.5), Operations (FEP 1.1.6) and Closure (FEP 1.1.7), rather than the details of these processes.
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 scheduling and planning of activities to develop and operate a repository influence the conditions of the wastes and barriers at the time of closure (e.g. the heat emitted by a given kind of heat-generating radioactive waste at the time of repository closure will depend upon the length of time between generation of the waste and closure). The initial condition of the waste and barriers at the time of closure (FEP 1.1.7) will then influence the long-term performance of the barrier system and hence safety e.g. decay of activity and heat production from the wastes, material degradation, chemical and hydraulic changes during the operational phase. The development and operation of a repository (FEP 1.1.6) needs to be scheduled and planned to emplace the wastes and engineered barriers in a way that promotes long-term performance and safety. Monitoring (FEP 1.1.10) needs to be scheduled and planned to obtain information that is relevant for assessing long-term performance and safety.
2000 List
A reference to the related FEP(s) within the 2000 NEA IFEP List.
Related References
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IAEA (), Disposal of Radioactive Waste, Specific Safety Requirements No. SSR-5, International Atomic Energy Agency, Vienna, ISBN 978–92–0–103010–8, http://www-pub.iaea.org/MTCD/publications/PDF/Pub1449_web.pdf
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IAEA (), Planning and Design Considerations for Geological Repository Programmes of Radioactive Waste, IAEA-TECDOC-1755, International Atomic Energy Agency, Vienna