Technischer Bericht NTB 13-01

Standortunabhängige Betrachtungen zur Sicherheit und zum Schutz des Grundwassers – Grundlagen zur Beurteilung der grundsätzlichen Bewilligungsfähigkeit einer Oberflächenanlage für ein geologisches Tiefenlager

This report explains how the protection of man and the environment can be assured for the surface facility of a deep geological repository. The report is intended primarily for the federal authorities, but also provides important information for the siting Cantons and siting regions. Nagra has also prepared an easily understandable brochure on the topic for the general public.

The report was prepared at the request of the Swiss Federal Office of Energy (SFOE), with the aim of allowing the responsible federal authorities to evaluate, in a general manner, the aspects of safety and groundwater protection during the construction and operation of the surface facility of a geological repository, and the ability of the facility to fulfill the licensing require­ments. The information is based on preliminary design concepts. The report presents the main features of a surface facility (design, activities), taking into account the waste to be emplaced in the repository and the potential conditions at the site. It is not a formal safety report for a facility at a real site within the context of licencing procedures as specified in the nuclear energy legislation.

In line with the different legal and regulatory requirements, the following aspects are the subject of a qualitative analysis for the surface facility:

  • Nuclear safety and radiological protection during operation
  • Safety with respect to conventional (non-nuclear) accidents during operation and
  • Protection of the groundwater during the construction and operational phases.

The analysis highlights the fundamental requirements relating to the design of the surface facility, the operating procedures and the waste to be emplaced that have to be implemented in order to ensure the safety and protection of the groundwater. The influence of site-specific features and factors on the safety of the surface facility and on a possible impact on groundwater is also considered.

To summarise, the report reaches the conclusion that the surface facility can be constructed and operated safely, provided the site selected, the design of the facility and the operating pro­cedures are appropriate. It also concludes that, even if the surface facility is located in an Au groundwater protection zone, it will not present any particular hazard to the groundwater. The surface facility is therefore considered to fulfill the licensing requirements with regard to safety and groundwater protection.