The Sectoral Plan for Deep Geological Repositories regulates the search for suitable siting regions for deep geological repositories in Switzerland, which is conducted in three stages (BFE 2008). The Sectoral Plan process concludes with the end of Stage 3, i.e., with the approval of the object sheet²⁹ by the Federal Council. At the same time, the Federal Council decides on the granting of the general licence.

After the site has been approved in the general licensing procedure, construction and operation licenses are required for constructing and operating the repository (based on nuclear energy legislation). After completion of the operating and monitoring periods, a permit for closure must be applied for and issued by the Federal Council.

The background for preparing the application for future licences is provided by experience gained in preparing the general licence application, experience from international projects and information on newly developed technologies. However, the following main points are expected:

• Construction licence: The construction licence showcases a detailed plan of the future facilities and a plan for closure. The construction licence also specifies the key elements for technical implementation. This includes the test areas, which, together with the main repository and the pilot repositories, form integral parts of the geological repository.

  With the framework of preparing the construction licence and its related permits, a stage-appropriate optimisation is carried out for the selection of the engineered barriers (disposal containers, backfilling, sealing) and the design of the underground repository architecture, as well as the technical implementation of the project.

  The construction licence application also provides the possibility to optimise and adapt the repository infrastructure.

• Operating licence: The operating licence specifies the definitive protection zone³⁰ of the deep geological repository and the permissible capacity of the facility. It also sets out measures for monitoring the environment and the stages of commissioning, the start of which requires prior clearance by the regulatory authorities. The operating licence also specifies requirements relating to limits for the activity of the waste to be disposed of. The emplace­ment of waste packages in a repository requires approval by ENSI (ENSI 2023). The sealing technology for any sealing elements that have not been tested in advance is tested at this point, and their functionality during repository operation is demonstrated. Technology that would allow, if needed, the pre-closure retrieval of waste packages without undue effort must also be demonstrated, including the introduction and removal of backfill materials.

  Once the operating licence has been granted, waste emplacement in the repository begins. Safety checks are carried out periodically during operation.

  The monitoring period begins once emplacement is complete. The application for de­commissioning of the facilities and structures at the surface is also prepared and submitted.

• Closure of the repository: After the end of the monitoring period, the Federal Council authorises closure work provided that the permanent protection of humans and the environ­ment can be ensured. After final closure, the Federal Council may order further, temporary monitoring. At this time, or after expiry of the monitoring period, the Federal Council determines that the repository is no longer subject to nuclear energy legislation.

  With the application for repository closure, the final decision on the preferred closure variant is made. For this, the repository closure plan and an updated project plan for the monitoring period are to be submitted.