In 2003, the Danish Parliament gave its consent for the Government to start preparing a 'basis for decision' for a final repository for Denmark's low- and intermediate level radioactive waste.

The 'basis for decision' was presented for Parliament in January 2009. It describes the principles on safety and environmental concerns which set the frame for the establishment of the final repository.

The 'basis for decision' outlines three parallel studies which are to be carried out prior to the establishment of the repository. 

1. an investigation of repository concepts in relation to geology and safety analyses
2. a study on safe transportation of radioactive waste
3. a geological study describing areas in Denmark suitable as sites for a final repository.

Together, these three preliminary studies will constitute the basis upon which the final decisions on geological environment, repository concept, and repository location will be taken. 

The 'basis for decision' also states that the Danish radioactive waste must be stored on Danish territory and must hold the existing radioactive waste, the waste from the decommissioning, and the radioactive waste produced in Denmark for a number of years to come (from hospitals, universities and industry).

The 'basis for decision' recommends that the final repository should not depend on future generations to carry out safety procedures or monitor the waste. Furthermore, it is recommended that the process of finding the repository is characterised by high-quality information, openness and dialogue with the public.

The Ministery of Health has the overall responsiblity for the establishment of the repository. Responsibility for the preliminary studies is divided in three: DD is responsible for the repository concepts in relation to geology and safety analyses. The National Institute of Radiation Protection, SIS, is responsible for the study of transportation, and The Geological Survey of Denmark and Greenland, GEUS, is responsible for the geological studies of suitable areas for the repository.

When the three parallel preliminary studies have been concluded, a report will point to 20 possible locations for the repository. The numbers will then be narrowed down to 5-10 possible locations based on the joint conclusions of the preliminary studies.

The process towards the final repository will include public hearing where the public, NGOs, and local and regional authorities will be presented with the preliminary reports, the results of environmental investigation of the areas and any limitations on local planning set by the Ministry for the Environment.

The 'basis for decision' recommends that the 5-10 locations be further narrowed down to 2-3 locations before detailed environmental investigations are undertaken. This is due to the high cost of such investigations.

After the public hearings, Parliament will make a decision on the detailed environmental impact assessment (EIA) for the various locations and determine the final location for the repository.

Communicating with the public
During the process that leads to the decision on the location of the final repository, particular emphasis will be placed on informing and involving the public in the process. This may be done by publishing working papers and other material on relevant websites and by establishing contact with relevant NGOs, local authorities, Regions and associations, as well as holding public meetings and preparing relevant information material for the public.

DD's part of the preliminary investigations concerns the theoretical studies of three different concepts for the repository, each located in four different typical Danish geological settings. These studies run from October 2009 until April 2011. 

The potential spread of radioactive material to the environment will be modeled for a number of scenarios, and safety analyses will be carried out covering each combination. The final report will include considerations on design, construction and materials for the repository building, as well as considerations on the requirements for waste conditioning. It will also consider the question of reversibility and options for the future expansion of the repository as well as economic perspectives for the different repository concepts.

The process is planned to be iterative in the sense that waste conditioning and the concept and design of the repository will be reviewed and reconsidered until at least one, but preferably several safe combinations of repository concept, design, waste conditioning and typical Danish geological settings have been arrived at. The combinations which are found acceptable with respect to safety and cost will be identified and recommended for further process of finding a suitable repository. In addition, the final report will include estimates of the cost of setting up the repository.

The repository must be designed and located so there is a high probability that the radioactive waste will remain isolated from human beings and the environment for a period of at least 300 years. The repository will contain a number of materials, such as e.g. lead and cadmium, which will remain a hazard to the environment after the radioactivity is no longer a problem, so it is possible that the repository will be nominated as a repository for hazardous waste at that time.

In October 2009, Danish Decommissioning contracted COWI environmental and engineering consultants to carry out the technical side of the preliminary studies under the supervision of DD. In this work, COWI will collaborate with STUDSVIK AB, ENVIROS environmental consultants, and Hasløv and Kjærsgaard architects and town planners.

Read more details of repository concept and geology

Read more about the safety analyses

The radioactive waste is estimated to a total amount of up to 10,000 m³ and can be grouped as follows:

• Decommissioning waste from the nuclear facilities at Risø
• Existing waste of low activity originating from the operations at the nuclear facilities at Risø and from external users
• Existing waste of intermediate activity originating from the nuclear facilities at Risø
• Special waste (mainly spent fuel used for post irradiation experiments and larger α-sources)
• Contaminated concrete and tailings (the latter classed as potential waste only)

A large part of the waste has been conditioned in 210-litre concrete-lined waste drums. Waste packed in large ISO or steel containers has not yet been conditioned. The conditioning of the 'special waste' in particular will depend on the choice of repository concept.