Description

The continuous or periodic observation of a relevant property over a specified time periods. This includes monitoring that is carried out during site investigation, construction, operation and after closure of sections of, or the total, repository. This includes monitoring of parameters related to long-term safety and performance, as well as monitoring undertaken for operational safety reasons that might have an impact on long-term safety. The extent and requirement for such monitoring activities may be determined by a number of factors, such as repository design, geological setting, regulations and stakeholder requirements.

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.

Monitoring should improve confidence in performance and safety assessment models, if predictions agree with monitoring outcomes. If there is poor agreement, monitoring could play a role in developing better process understanding and ultimately improved models. Monitoring could potentially influence mitigating actions in the event that unexpected behaviour of the repository is identified. The timing and nature of these mitigating actions has the potential to influence repository performance and safety. Certain kinds of monitoring involve invasive techniques, such as borehole drilling, which must be undertaken in such a way that repository performance and safety are not compromised.

2000 List

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

1.1.11

Related References