Description
The accidents and unplanned events during construction, operation and closure that might have an impact on long-term performance and safety of the repository. Accidents and other unplanned events are those events outside the range of normal operations although the possibility that certain types of accident may occur should be anticipated in repository operational planning. Unplanned events include deliberate deviations from operational plans, e.g. in response to an accident, unexpected geological events or unexpected waste arising during operations.
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
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.
Accidents and unplanned events during construction, operation and closure could have one or more performance/safety-relevant consequences: damage to waste packages; poor emplacement of wastes; inadequate implementation of the engineered barrier system (EBS); and damage to the geosphere barrier (e.g. if there is a rockfall). If mitigating actions are not taken, then post-closure performance and safety could be impaired by such accidents and unplanned events.
2000 List
A reference to the related FEP(s) within the 2000 NEA IFEP List.
Related References
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Grundfelt B (), Radiological consequences of accidents during disposal of spent nuclear fuel in a deep borehole, SKB Report P-13-13, http://www.skb.com/publication/2641868/P-13-13.pdf