Description

Any airborne, surface or other remote investigations of a repository site after repository closure, which does not involve disturbing the subsurface environment (except for the transient, limited extent resulting from seismic techniques).

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.

This FEP excludes all intrusive site investigation activities such as drilling and mining, which are covered by FEP 1.4.5 and FEP 1.4.6, respectively.

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.

Un-intrusive site investigations would yield information about the subsurface in the area around a repository that could influence whether intrusive activities are undertaken to the detriment of repository performance and safety. The information obtained from un-intrusive site investigations could provide a motivation to undertake invasive activities (see also FEP 1.4.4), or alternatively provide a reason for not undertaking such activities. For example, if it is revealed that an ore deposit occurs near the repository there could be a motivation to proceed with invasive site investigations leading potentially to mining. Conversely, if the un-intrusive site investigations identified a repository about which knowledge and / or records had been lost, then a decision might be taken not to proceed with invasive activities. If there is a motivation to proceed with invasive activities, decisions about the kinds of invasive activities to undertake could be based on information from un-intrusive site investigations. Information obtained by the un-intrusive site investigations will affect the likelihood that these invasive activities will compromise the integrity of the repository or provide pathways for the transport of radionuclides and / or other contaminants from the subsurface to the biosphere.

2000 List

A reference to the related FEP(s) within the 2000 NEA IFEP List.

1.4.03

Related References