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GEOSAF Part II Task Group Activities

Core Group


The objective of the core group was to:

  • Develop basic supporting materials on relevant issues related to the integration of operational and long term safety in the safety case for geological disposal facilities.
  • Revise the materials taking into account the discussions in plenary meetings, and propose plans for the next plenary meeting potentially addressing new topics


Core group meetings were held at least twice in between plenary meetings. The group developed the arguments focusing on the concept of an "initial state" of a disposal facility, which tries to express the state of the system at the time of closure for post-closure safety assessment purposes. During the operational period revisions to the original design assumptions (e.g. barrier functions, material selections, configurations, etc.) are likely to occur and which can affect the assessment of post-closure safety. As the disposal project progresses through siting, design, construction, operation and closure, it is supposed that the operator will regularly update the safety case taking account lessons learned and increased knowledge. These updated safety cases, or the need for them, are likely to be subject to regulatory review or approval. At different points in time, including the time of closure of the disposal facility, the operator will have to ensure that the safety case demonstrates the safety performance with a reasonable level of confidence that the facility will deliver the required level of protection to humans and the environment in the long-term.

The technical document, which the core group was responsible for drafting, describes the key aspects to consider in order to ensure the safety objectives can be met throughout the development of the disposal facility, as well as proposing an approach for combining operational safety and post-closure safety into the safety case.

Upon completion of the project, the final version of the document will be published as an IAEA TECDOC.

Task Group on Operational Safety


At the plenary meeting in 2014, it was decided to set up a task group specially focused on operational safety. The task group aims to address the following questions:

  • Does the IAEA propose to develop a comprehensive set of guidance documents on how Member States can address the operational safety requirements underlined in the existing IAEA Safety Standards?
  • Are there any gaps in the IAEA existing documentation as to the achievement of the practical implementation of the existing requirements?
  • Among these gaps - if any - is there any other source of documentation from other international organizations and/or national schemes that in practice may fill such gaps?

Basic material for this task group include highlighted work produced during the recent EU SITEX (Sustainable network of Independent Technical EXpertise for radioactive waste Disposal) project.


Two task-group meetings were held before the plenary meeting in 2015. The task-group prepared a draft report which provided recommendations to the IAEA to potentially develop the rationale for further guidance in specific areas. The draft report was presented at the plenary meeting in 2015 where it has been finalized alongside with the GEOSAF Part II report and the technical document prepared by the core group.

In order to meet the objectives of this activity the task group has:

  • Assembled a list of existing IAEA Safety Requirements applicable to operational safety
  • Assembled a list of other IAEA publications arising from areas outside the field of geological disposal facilities’ safety and select relevant documents
  • Identified gaps, prioritize them and prepare a proposal to address the possible need for further guidance

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| Last update: Wednesday, 28 June, 2017.