1. Safety Case: German Approach
[from ISIBEL to KOSINA]
Jens Wolf1
7th US/German Workshop on
Salt Repository Research, Design and Operation
Washington, DC
September 7-9, 2016
ABSTRACT
During the last decade the concept of the Safety Case has been internationally established. The
Safety Case is a compilation of evidence, analyses and arguments that quantify and substantiate a
claim that a repository will be safe. The Safety Case evolves stepwise from a preliminary stage
into a more and more comprehensive stage. In Germany the idea of the Safety Case for the disposal
of HLW has been discussed and developed in the context of R&D projects. Typical questions of
Safety Case R&D are high-level analyses such as: How to achieve safety? How to demonstrate
safety? How to manage uncertainties? How to communicate safety?
Starting from the general German regulatory requirements for the disposal of HLW, a
methodological approach has been developed in several R&D projects, e.g. ISIBEL, that allows
the derivation of a safety concept for a repository for domal salt. The safety concept is based on
the safe containment of radioactive waste in a containment-providing rock zone (CRZ). On the
basis of a few guiding principles, specific objectives were devised, which were used to identify
strategic measures. These measures provide the basis for the detailed design and layout of the
repository. A scenario development methodology was developed, which is an important tool for
the management of uncertainties and forms the basis for the safety assessment. Each scenario is
described in detail by FEP and their characteristics. Key elements of the safety assessment are the
integrity proofs for the geological and geotechnical barriers and the analysis of the backfill
compaction. The potential releases of radionuclides from the CRZ in the derived scenarios were
evaluated against radiological safety indicators.
The most recent R&D work on Safety Case issues is the project KOSINA concerning the HLW
disposal in bedded salt in Germany. In a first step a safety concept for a repository in bedded salt
was established and compared to the safety concept for domal salt repositories. The presentation
gives an introduction to the Safety Case R&D in Germany including recent results of the ISIBEL
and KOSINA projects.
1Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH, Theodor-Heuss-Straße 4,
381022 Brauschweig, jens.wolf@grs.de
![Safety Case: German Approach
[from ISIBEL to KOSINA]
Jens Wolf1
7th US/German Workshop on
Salt Repository Research, Design and Operation
Washington, DC
September 7-9, 2016
ABSTRACT
During the last decade the concept of the Safety Case has been internationally established. The
Safety Case is a compilation of evidence, analyses and arguments that quantify and substantiate a
claim that a repository will be safe. The Safety Case evolves stepwise from a preliminary stage
into a more and more comprehensive stage. In Germany the idea of the Safety Case for the disposal
of HLW has been discussed and developed in the context of R&D projects. Typical questions of
Safety Case R&D are high-level analyses such as: How to achieve safety? How to demonstrate
safety? How to manage uncertainties? How to communicate safety?
Starting from the general German regulatory requirements for the disposal of HLW, a
methodological approach has been developed in several R&D projects, e.g. ISIBEL, that allows
the derivation of a safety concept for a repository for domal salt. The safety concept is based on
the safe containment of radioactive waste in a containment-providing rock zone (CRZ). On the
basis of a few guiding principles, specific objectives were devised, which were used to identify
strategic measures. These measures provide the basis for the detailed design and layout of the
repository. A scenario development methodology was developed, which is an important tool for
the management of uncertainties and forms the basis for the safety assessment. Each scenario is
described in detail by FEP and their characteristics. Key elements of the safety assessment are the
integrity proofs for the geological and geotechnical barriers and the analysis of the backfill
compaction. The potential releases of radionuclides from the CRZ in the derived scenarios were
evaluated against radiological safety indicators.
The most recent R&D work on Safety Case issues is the project KOSINA concerning the HLW
disposal in bedded salt in Germany. In a first step a safety concept for a repository in bedded salt
was established and compared to the safety concept for domal salt repositories. The presentation
gives an introduction to the Safety Case R&D in Germany including recent results of the ISIBEL
and KOSINA projects.
1Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH, Theodor-Heuss-Straße 4,
381022 Brauschweig, jens.wolf@grs.de](https://image.slidesharecdn.com/03wolfsafetycasegermanapproach-160923183047/85/03-wolf-safety-case-german-approach-1-320.jpg)
