Investigation of Surface Exploration Programs for Hydrological, Hydrogeological and Hydrogeochemical Issues in the Site Selection Procedure

Abstract. The project “Investigation of Surface Exploration Programmes for Hydrological, Hydrogeological and Hydrogeochemical Issues in the Site Selection Procedure” summarizes the measurement methods that can be used for surface exploration of site regions and compares them with the measurement parameters as given in the Repository Site Selection Act (StandAG). Based on this, an orientation framework was developed that can support the evaluation of actual exploration programs. This project is limited to those measurement parameters that result from §§ 22–24 in conjunction with the Annexes 1–11 of the StandAG for the surface exploration of hydrological, hydrogeological and hydrogeochemical characteristics of site regions. In a first step, definitions of terms which are subject to interpretation were identified in the StandAG and advice was provided on how to deal with them and, in some cases, justified proposals for interpretation within the framework of this project were given. As a result, hydrological, hydrogeological and hydrogeochemical parameters were presented that were derived directly from the StandAG, as well as those that are not explicitly mentioned in the StandAG but are necessary for a detailed characterization of the rock formations in a site region. The next step was to identify measurement methods to be used for surface exploration of hydrological, hydrogeological and hydrogeochemical parameters. In particular, hydrogeologic and (borehole) geophysical methods were considered in the context of field measurements and laboratory investigations as well as field and laboratory tests for the determination of hydrogeochemical parameters. These measuring methods were described with respect to their measuring principle, the respective limits, the technical effort as well as the advantages and disadvantages of their application. Possible combinations with other measuring methods as well as a potential need for additional research and development for use in surface exploration programs were also presented. Considering the boundary conditions and dependencies for different rock types and necessary exploration depths, the measuring methods were assigned to the relevant parameters with respect to their applicability. In most cases, several methods are suitable for the determination of a specific parameter. Combining different physically independent methods can limit the range of variation of the measured variables and significantly increase the reliability of the results. The resulting compilation of measurement methods was used in the last step to establish an orientation framework. This framework contains the essential requirements for a complete documentation and quality assurance of the measurements and sampling and derives fundamental factors influencing the quality and quantity of the parameters. The orientation framework also refers to various factors that may influence the selection of suitable measuring methods for the surface exploration of the parameters as well as the determination of appropriate measuring network densities and measurement intervals. The measurement network densities selected at the beginning of the exploration are usually adjusted based on increasing knowledge of the site-specific geological conditions. This step-by-step procedure, which has proven successful in geological exploration programs, was also emphasized in the orientation framework, as it gradually increases the level of knowledge, the level of detail and thus the reliability of the measurement results.

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Geoscientific Characterization and Interpretation (Geosynthesis) within the Preliminary Safety Assessment in the German Site-Selection Procedure for a High-level Nuclear Waste Repository

Safety of Nuclear Waste Disposal ◽

10.5194/sand-1-45-2021 ◽

2021 ◽

Vol 1 ◽

pp. 45-46

Author(s):

Sönke Reiche ◽

Reinhard Fink ◽

Nils-Peter Nilius

Keyword(s):

Radioactive Waste ◽

Nuclear Waste ◽

Site Selection ◽

Selection Procedure ◽

Nuclear Waste Repository ◽

Geological Processes ◽

Geological Conditions ◽

Surface Exploration ◽

Waste Repository ◽

High Level

Abstract. After implementation of the Repository Site Selection Act (StandAG) in 2017, the Federal Company for Radioactive Waste Disposal (BGE), as the German waste management organization, started the site selection procedure for a nuclear repository for high-level radioactive waste in Germany. On the way towards the repository site with the best possible safety, the site selection procedure is required to be a participatory, transparent, learning and self-questioning process based on scientific expertise. With the Subareas Interim Report published in 2020, first results were presented outlining subareas with favourable geological conditions in preparation for defining the siting regions for surface exploration. Currently, one of the main tasks in the site selection procedure is to establish a detailed geoscientific synthesis (Geosynthesis) for each subarea. The Geosynthesis contains all geological information for the characterization of each subarea and hence serves as the foundation for the subsequent analysis within the representative preliminary safety assessments (rvSU) and the geoscientific consideration criteria. Based on this information, all areas within the subareas will be evaluated to find the siting regions for surface exploration. The Geosynthesis includes a description of the regional geology focusing on the host rock, the overburden and relevant geological processes that may affect the potential nuclear waste repository in the next 1 million years. The data for the Geosynthesis are mostly compiled from state authorities and include 3-D geologic models, regional maps and cross-sections, bore hole data (e.g. geophysical logs) and seismic data. Furthermore, it is necessary to digitize, process, interpret and evaluate the aforementioned data using the available knowledge from the scientific literature in the context of the site selection procedure.

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Development of a database for the analysis of the disposal system in the representative preliminary safety analysis

Safety of Nuclear Waste Disposal ◽

10.5194/sand-1-39-2021 ◽

2021 ◽

Vol 1 ◽

pp. 39-40

Author(s):

Eva-Maria Hoyer ◽

Paulina Müller ◽

Phillip Kreye ◽

Christoph Behrens ◽

Marc Wengler ◽

...

Keyword(s):

Radioactive Waste ◽

Site Selection ◽

Selection Procedure ◽

Crystalline Rock ◽

Radioactive Waste Disposal ◽

Future Evolution ◽

Technical Parameters ◽

Geological Setting ◽

Geological Conditions ◽

High Level

Abstract. The Federal Company for Radioactive Waste Disposal (BGE) is the German waste management organisation responsible for implementing the search for a site with the best possible safety for the disposal of high-level radioactive waste for at least 1 million years, following the amendments of the Repository Site Selection Act in 2017. The selection procedure is meant to be a participatory, transparent, learning and self-questioning process based on scientific expertise. It consists of three phases with an increasing level of detail. The first step of the first phase of the site selection procedure was completed in September 2020 and resulted in the identification of 90 subareas that give reason to expect favourable geological conditions for the safe disposal. The potentially suitable subareas cover approximately 54 % of Germany and are located in three different host rocks: rock salt (halite), claystone and crystalline rock. The second step of phase one is currently in progress and includes the so-called representative preliminary safety analyses that aim to assess the extent to which the safe containment of the radioactive waste can be expected. Representative preliminary safety analyses are one of the foundations for deciding whether an area will be considered for surface-based exploration in the next phase of the site selection procedure. Within the preliminary safety analyses, the behaviour of the disposal system is analysed in its entirety, across all operational phases of the repository and under consideration of possible future evolution of the disposal system with respect to the safe containment of the radioactive waste. The development of a database is described, which aims to systematically document and provide the framework needed for the analyses of the disposal systems in the subareas regarding the safe containment of the radionuclides over the assessment period of 1 million years. This database includes the vast amount of information about the different components of the disposal system. This includes also the geological setting, the technical conception of the repository and compilations of values for the physical, geoscientific, and technical parameters characterising the various barriers of the disposal system. Furthermore, a self-contained derivation of expected and deviating future evolution of the disposal system and its geological setting is included; following the so-called features, events and processes (FEP) strategy.

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Section 14 StandAG – Identification of siting regions and associated challenges

Safety of Nuclear Waste Disposal ◽

10.5194/sand-1-49-2021 ◽

2021 ◽

Vol 1 ◽

pp. 49-50

Author(s):

Lisa Seidel ◽

Marc Wengler

Keyword(s):

Radioactive Waste ◽

Phase I ◽

Site Selection ◽

Selection Procedure ◽

Radioactive Waste Disposal ◽

Second Step ◽

High Level Radioactive Waste ◽

Surface Exploration ◽

Safety Assessments ◽

High Level

Abstract. With the publication of the subarea interim report on sub-regions on 28 September 2020, the Federal Company for Radioactive Waste Disposal (BGE), as the implementer of the German site selection procedure, has completed the first step of phase I in due time. The second step of phase I is the identification of siting regions for surface exploration. In the following step 2 of phase I, the determination of siting regions for surface exploration will be carried out based on the interim results of the first step of phase I in accordance with section 14 of the regulating law (StandAG). A central component of this second step of phase I is the representative preliminary safety assessments pursuant to section 27 StandAG, the ordinances on “Safety Requirements” (EndlSiAnfV) and “Preliminary Safety Assessments” (EndlSiUntV), which are carried out for each of the sub-regions. Based on the results of the preliminary safety assessments and the renewed application of the geoscientific weighting criteria (section 24 StandAG), siting regions will be identified that have the potential to become the site with the best possible safety for a repository for high-level radioactive waste. During the second step of phase I, the planning scientific consideration criteria (section 25 StandAG) can be applied for the first time. The path to the siting regions for surface exploration can be accompanied by various challenges related to geoscientific, methodological and also societal questions. For example, the application of the representative preliminary safety assessments may be more challenging in larger subareas compared to smaller ones as subsurface properties are likely to be more variable. In this context, areas with little data coverage for example, and the treatment of these areas in the procedure may pose another challenge. Therefore, sound methodological concepts must be developed for performing the representative preliminary safety assessments as well as for applying the geoscientific weighting criteria. Furthermore, the German site selection procedure defines special requirements (section 1 StandAG): the implementation of the participatory, science-based, transparent, self-questioning and learning procedure poses challenges to all stakeholders of the procedure on the way to the best possible disposal of high-level radioactive waste.

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Preliminary safety analyses in the high-level radioactive waste site selection procedure in Germany

Advances in Geosciences ◽

10.5194/adgeo-56-67-2021 ◽

2021 ◽

Vol 56 ◽

pp. 67-75

Author(s):

Eva-Maria Hoyer ◽

Elco Luijendijk ◽

Paulina Müller ◽

Phillip Kreye ◽

Florian Panitz ◽

...

Keyword(s):

Radioactive Waste ◽

Site Selection ◽

Selection Procedure ◽

Crystalline Rock ◽

Radioactive Waste Disposal ◽

High Level Radioactive Waste ◽

Long Term Storage ◽

Geological Conditions ◽

High Level ◽

A Site

Abstract. The Federal Company for Radioactive Waste Disposal (BGE) is responsible for the search for a site with the best possible safety for the disposal of high-level radioactive waste in Germany. The site selection procedure is regulated in a law that was adopted by the German Federal Parliament (Repository Site Selection Act – StandAG, 2017, last updated 2020) and aims to be a participatory, transparent, learning, and self-questioning process based on scientific expertise. The first step of the first phase of the site selection procedure was completed in September 2020 and resulted in the identification of sub-areas that give reason to expect favorable geological conditions for the long-term storage of nuclear waste in the subsurface. These sub-areas cover approximately 54 % of Germany and are located in three different host rocks: rock salt – halite, claystone, and crystalline rock. The challenge for the next step is to find suitable siting regions within the previously determined sub-areas that are then considered further in the next phase of the site selection procedure. In the following, the methodology of the so-called representative preliminary safety analyses is described, which constitute one of the tools to identify siting regions, and some first insight on how they are planned to be implemented in practice is given.

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Preliminary safety assessments in the high-level radioactive waste site selection procedure in Germany

10.5194/egusphere-egu21-9429 ◽

2021 ◽

Author(s):

Eva-Maria Hoyer ◽

Christoph Behrens ◽

Merle Bjorge ◽

Julia Dannemann ◽

Dennis Gawletta ◽

...

Keyword(s):

Radioactive Waste ◽

Site Selection ◽

Selection Procedure ◽

Crystalline Rock ◽

Radioactive Waste Disposal ◽

Seismic Exploration ◽

High Level Radioactive Waste ◽

Geological Conditions ◽

Safety Assessments ◽

High Level

The Federal Company for Radioactive Waste Disposal mbH (BGE mbH) is as Germans waste management organization responsible to implement the search for a site with the best possible safety for the disposal of high-level radioactive waste for at least one million years, following the amendments of the Repository Site Selection Act in 2017. The selection procedure is meant to be a participatory, transparent, learning and self-questioning process based on scientific expertise.This contribution will provide an overview of the methodology of the forthcoming preliminary safety assessments as a major part of the next steps in the site selection procedure. This procedure overall consists of three phases with increasing level of detail for identification of the best site. The first phase consists of two steps. The objective of the first step was to determine sub-areas in the three considered host rocks, salt (halite), clay and crystalline rock, by applying legally defined exclusion criteria, minimum requirements and geoscientific weighing criteria. 90 sub-areas that cover approximately 54&#160;% of the area of Germany were identified due to their general suitable geological conditions. The result was published in September 2020.The second step of phase one is currently in progress and consists of representative preliminary safety assessments that aim to assess the safety of the repository system as well as its robustness. The requirements for the preliminary safety assessments in the site selection procedure are defined by a governmental directive released in October 2020. Representative preliminary safety assessments have to be performed for each sub-area and consist of the compilation of all geoscientific information relevant to the safety of a repository, the development of preliminary safety and repository concepts and the analysis of the repository system. In addition, a systematically identification and characterization of uncertainties has to be undertaken and the need for exploration, research and development must be determined. The application of the representative preliminary safety assessments as well as the following renewed application of geoscientific weighing criteria will lead to the identification of siting regions within the larger sub-areas of step one. These regions will be considered, first for surface-based geoscientific and geophysical exploration, including i.e. seismic exploration and drilling of boreholes. Subsequently the last phase of the site selection will proceed with subsurface exploration. Finally, all suitable sites will be proposed and the German government will decide the actual site. This process is expected to be finalized in 2031.

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Preliminary safety assessments in the high-level radioactive waste site selection procedure in Germany

Safety of Nuclear Waste Disposal ◽

10.5194/sand-1-37-2021 ◽

2021 ◽

Vol 1 ◽

pp. 37-38

Author(s):

Eva-Maria Hoyer ◽

Phillip Kreye ◽

Thomas Lohser ◽

Wolfram Rühaak

Keyword(s):

Radioactive Waste ◽

Site Selection ◽

Selection Procedure ◽

Radioactive Waste Disposal ◽

Seismic Exploration ◽

High Level Radioactive Waste ◽

Geological Conditions ◽

Minimum Requirements ◽

Safety Assessments ◽

High Level

Abstract. The Federal Company for Radioactive Waste Disposal (BGE) is a German waste management organization responsible for implementing the search for a site with the best possible safety for the disposal of high-level radioactive waste for at least 1 million years, following the amendments of the Repository Site Selection Act in 2017. The selection procedure is meant to be a participatory, transparent, learning and self-questioning process based on scientific expertise. This contribution provides an overview of the methodology of the forthcoming preliminary safety assessments as a major part of the next steps in the site selection procedure. This procedure overall consists of three phases with increasing levels of detail for identification of the best site. The first phase consists of two steps. The objective of the first step was to determine sub-areas in the three considered host rocks, salt (halite), claystone and crystalline host rock, by applying legally defined exclusion criteria, minimum requirements and geoscientific weighing criteria. A total of 90 sub-areas that cover approximately 54 % of the area of Germany were identified due to their general suitable geological conditions. The results were published in September 2020. The second step of phase one is currently in progress and includes representative preliminary safety assessments that aim to assess the extent to which the safe containment of the radioactive waste can be expected in the investigated sub-area. The requirements for conducting preliminary safety assessments in the site selection procedure are defined by a governmental directive released in October 2020. Representative preliminary safety assessments have to be performed for each sub-area and consist of the compilation of all geoscientific information relevant to the safety of a repository, the development of preliminary safety and repository concepts and the analysis of the disposal system. In addition, a systematic identification and characterization of uncertainties has to be undertaken and the need for exploration, research and development must be determined. The application of the representative preliminary safety assessments as well as the following renewed application of geoscientific weighting criteria will lead to the identification of siting regions within the larger sub-areas identified in step one. These regions will be considered, first for surface-based geoscientific and geophysical exploration, including e.g. seismic exploration and drilling of boreholes. Subsequently, the last phase of the site selection will proceed with subsurface exploration. Finally, all suitable sites will be proposed and the German government and parliament will decide the actual site. This process is expected to be finalized in 2031.

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