Deep geological repositories are designed for the safe storage of spent nuclear fuel (after it has been declared as radioactive waste) and radioactive waste that cannot be stored in near-surface repositories.
The primary concern for the implementation of a proposed technical design is to demonstrate both operational and long-term safety which, owing to the nature of the waste stored, is on the order of hundreds of thousands of years. When evaluating the long-term safety (following closure) even extremely unlikely processes and eventualities should be considered as well as events or accidents that might occur within the next hundreds of thousands of years.
A number of input and boundary conditions will influence the technical design of a deep geological repository; these conditions can be divided into four groups:
These relate primarily to the quantity and characteristics of the waste and the form in which it will be stored. These considerations may include a decision on whether reprocessed or non-reprocessed fuel will be stored and whether the hot cell, which is used for transferring the fuel into storage casks, will be located within the deep geological repository complex or, alternatively, whether already filled storage casks will be delivered to the repository following preparation elsewhere.
Requirements and limitations arising from the characteristics of the disposal site
With respect to the design of the underground complex, characteristics relating to the quality of the rock mass are of particular importance. This includes data on the progression of the major faults and deformation zones, the geotechnical properties of the rock massif, the range of the depth of denudation processes and the chemical composition of the groundwater. With regards to the surface complex, considerations include, the morphology of the terrain, which may have an influence on its areal extent as well as on the location of certain important and support technologies, the potential for connection to the local infrastructure system, etc. Other important conditions relate to specific environmental constraints such as local weather conditions and the surrounding landscape.
Deep geological repositories are considered nuclear facilities consisting of both surface and underground complexes. Therefore, it falls within the competence of, and must comply with all relevant requirements concerning, nuclear, mining, civil engineering and environmental impact legislation.
These considerations relate primarily to understanding the concerns of the general public regarding the incorporation of the complex into the surrounding countryside and minimising the impacts of construction on the local environment.
More information on the deep geological repository project design is available HERE.
Strategic Action Plan is available HERE.