Description
Any human activities that may be carried out in the surface environment, other than water management, which potentially change the disposal system to the extent that this affects its performance and safety. Examples include: changes in land use; quarrying and trenching; excavation for industrial purposes such as construction of a building; excavation for archaeological purposes; residential and road construction; and major earthmoving projects, such as construction of dikes and dams.
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
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.
FEPs related to water management, such as following dam construction, are excluded; they are covered by FEP 1.4.9.
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.
Surface activities are relevant to repository performance and safety because they could: 1) influence the locations of groundwater recharge and discharge and the recharge rates (which could in turn influence the groundwater flow regime in and around a repository); 2) influence the chemistry of water that recharges the groundwater system (which could in turn influence the chemistry of groundwater in and around a repository); 3) influence mechanical loading on the ground around a repository (e.g. if large buildings are constructed or quarries are excavated); 4) influence patterns of surface drainage, erosion and sedimentation, with consequent influences on topography; 5) influence the pathways by which receptors could be exposed to radionuclides or other contaminants originating in a repository; and 6) influence the nature of receptors that could be impacted by radionuclides or other contaminants originating in a repository. Many surface activities will influence groundwater recharge by changing the permeability of near-surface media (e.g. construction of buildings will reduce recharge) and distribution of soils and vegetation (which will affect water storage and evapotranspiration). Similarly, many surface activities have the potential to affect the chemistry of recharged waters, for example waste disposal in landfill, application of fertilizer during agriculture, or spillages of chemicals during industrial activities. Mechanical loads exerted by some surface activities, such as construction of large buildings or dams / reservoirs, could be considerable. In extreme cases seismicity could result (e.g. a M6.7 earthquake is thought to have been triggered by a dam at Koyna, India in 1967). Hydrological systems could be affected by surface activities such as land drainage or dam construction. Rates of erosion could be influenced by changing land use and by construction of structures. Some surface activities are intended to limit or modify erosion, for example rock bolting and shotcreting steep slopes to prevent landslips. These activities could collectively modify patterns of erosion and sedimentation thereby influencing future landforms. The ecosystems that could be impacted by radionuclides and / or other contaminants originating in a repository could reflect in part the surface activities that have been undertaken in an area; ecosystems in agricultural areas and urban areas will be very different. The effects of surface activities on hydrology, recharge, erosion and sedimentation, landforms, sediment types / rock types and ecosystems could potentially influence retardation and dispersion of radionuclides and other contaminants at the earth’s surface / near-surface. These effects could also influence the pathways by which organisms could be exposed to radionuclides or other contaminants.
2000 List
A reference to the related FEP(s) within the 2000 NEA IFEP List.
Related References
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NEA (), Future Human Actions at Disposal Sites, A Report of the NEA Working Group on Assessment of Future Human Actions at Radioactive Waste Disposal Sites, Nuclear Energy Agency/Organisation for Economic Cooperation and Development, ISBN 92-64-14372-6, https://www.oecd-nea.org/rwm/reports/1995/nea6431-human-actions.pdf