Phase I Step 2: Siting regions

The aim of Step 2 of Phase I of the site selection procedure is to identify siting regions. These regions are to be explored above ground as part of the search for a repository site for high-level radioactive waste in Germany.

On this page

• Safety analyses and areas fot methodological development
• Geoscientific consideration
• Theoretical planning consideration
• Proposed siting regions
   

The process of narrowing down and assessing siting regions consists of three key instruments:

1. representative preliminary safety analyses
2. geoscientific weighing criteria
3. planning-scientific weighing criteria

The starting point is the result of Step 1 of Phase I of the site selection procedure: the 90 sub-areas that the BGE identified in the Sub-areas Interim Report.

Four areas for methodological development therefore help the BGE to design a robust processing concept so that the representative preliminary safety analyses can be applied to all 90 sub-areas – in such a manner that, depending on the type of host rock, they can be compared with one another.

At the end of March 2022, the BGE published the progress of work on its methodology:

Abridged version for readers: Concept for carrying out representative preliminary safety analyses in accordance with the Repository Safety Investigation Ordinance (PDF, 235 KB) (PDF, 0,23MB)

This was discussed online until the end of May 2022. The online consultation and the opportunity to submit expert opinions come in addition to a series of events at which experts from the BGE explained the procedure and answered some initial questions. The aim is to develop a fundamental approach that takes account of the very different situations in the 90 sub-areas, on the one hand, while also ensuring that the same benchmark is used for measurements across the board.

In June, the BGE held another official event in order to give a final report on the suggestions and recommendations it received during the course of the public expert debate and the discussion as well as how it will now proceed.

Sequence of safety analyses

The procedure for a representative preliminary safety analysis consists of a sequence of seven elements:

• specification of investigation areas
• geosynthesis
• preliminary safety concept, including preliminary design of repository
• analysis of repository system
• comprehensive assessment of repository system
• assessment of uncertainties
• derivation of exploration and research requirements

Even here, some sub-areas may fall through the search grid and would therefore not be taken into consideration in the rest of the procedure, although favourable siting regions are identified by the second assessment instrument: the geoscientific weighing criteria.

Initially, the sub-areas can be narrowed down by means of the representative preliminary safety analyses, as these serve in particular to identify clearly unsuitable areas that are then excluded from consideration in the rest of the procedure. Further narrowing down of the sub-areas with a view to identifying siting regions is achieved by renewed application of the geoscientific weighing criteria.

The geoscientific weighing criteria are used to carry out a safety-related and comparative assessment and a comparison of areas. These criteria compare the safety of the areas identified in the representative preliminary safety analyses. Here, the aim is to identify the worse areas and to provide appropriate justification for their exclusion from the procedure. The methodology for applying the geoscientific weighing criteria is currently undergoing further development – and the progress of this work will be presented for public discussion in autumn 2022.