Description

An explosion resulting from the ignition of a flammable gas mixture in the waste package. Included are explosions resulting from gases produced from the corrosion and degradation of waste packages.

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.

An explosion involving a gas mixture within a waste package could potentially damage the package, possibly resulting in a loss of containment (where the package is initially sealed) or decreasing the ability of a package to retard movement of radionuclides or other contaminants (where the package initially does not provide complete containment (e.g. because it is vented), or where package integrity has already been lost). The explosion could also alter the characteristics of the waste form, thereby influencing its ability to release radionuclides or other contaminants (e.g. by fragmenting the waste form thereby increasing the surface area from which radionuclides could be released). An explosion may also provide a short-term force that drives radionuclides and other contaminants from the package. An explosion within a waste package could impact upon the functioning of surrounding engineered and / or natural barriers. For example, cementitious barriers may be fractured by the force of such an explosion.

2000 List

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

2.1.12

Related References