bluuebunny/crossref_metadata_2025 huggingface dataset:
Microscopic and spectroscopic investigations of uranium(VI) reduction by Desulfosporosinus hippei DSM 8344
Authors: Hilpmann Stephan , Steudtner Robin , Drobot Björn , Hübner René , Bok Frank , Stumpf Thorsten , Cherkouk Andrea
Published: November 2021

Abstract. Clay formations are potential host rocks for the long-term storage of
high-level radioactive waste in a deep geological repository. Bentonites are supposed to serve as backfill material, not only for a final disposal site in clay formations but also in crystalline rock. For a long-term safety assessment, various aspects must be taken into account. Besides geological, geochemical and geophysical considerations, naturally occurring microorganisms also play a crucial part in the environment of such a repository. In the event of a worst-case scenario when water enters the disposal site, they can interact with the radionuclides and change for example the chemical speciation or the oxidation state (Lloyd et al., 2002). Desulfosporosinus spp. are an important representative of anaerobic, sulfate-reducing microorganisms, which are present in clay formations as well as in bentonites. Various studies have shown that they play a major role in the microbial communities of these surroundings (Bagnoud et al., 2016; Matschiavelli et al., 2019). A closely related microorganism to the isolated species is Desulfosporosinus hippei DSM 8344, which was originally found in permafrost soil (Vatsurina et al., 2008). This bacterium was used to investigate its interactions with uranium(VI) especially regarding the reduction to the less mobile uranium(IV). Time-dependent reduction experiments in artificial Opalinus Clay pore water
(Wersin et al., 2011) (100 µM uranium(VI), pH 5.5) showed the
removal of about 80 % of the uranium(VI) from the supernatants within
48 h. Corresponding UV/Vis measurements of the dissolved cell pellets exhibited an increasing proportion of uranium(IV) in the cell-bound
uranium. Calculations with the inclusion of extinction coefficients led to a ratio of 39 % uranium(IV) after 1 week. Therefore, a combined
sorption-reduction process is a possible interaction mechanism. Time-resolved laser-induced luminescence spectroscopy verified the presence of two uranium(VI) species in the supernatant. A comparison with reference
spectra led to an assignment to a uranyl(VI) lactate and a uranyl(VI)
carbonate complex. The species distribution showed a decrease of the
proportion of the lactate species with time, whereas the proportion of the
carbonate species remained almost constant. Uranium aggregates are formed on the cell surface during the process, as
determined by transmission electron microscopy (TEM). Furthermore, uranium
occurs inside and outside the cells as well as vesicles containing uranium. These findings help to close existing gaps in a comprehensive safeguard
concept for a repository for high-level radioactive waste in clay
rock. Moreover, this study provides new insights into the interactions of
sulfate-reducing microorganisms with uranium(VI).
Identification and evaluation of processes for joint disposal of high level radioactive waste and low to intermediate level radioactive waste
Authors: Poller Andreas , Hardie Susie M. L. , Mayer Gerhard , Pijorr Marie , Poppei Joachim , Smith Paul , Urpi Luca , Wissmeier Laurin
Published: November 2021

Abstract. The on-going research project „Identification and evaluation of processes that can arise by disposing of both high level radioactive waste (HAW) and low to intermediate level radioactive waste (LAW/MAW) at the same site“ (GemEnd, FKZ 4719F10401), commissioned by the
Federal Office for the Safety of Nuclear Waste Management (BASE), is
concerned with the question which thermal, hydraulic, mechanical, chemical
and biological (THMCB) processes could be of importance for the long-term
safety of the geological repository for high level radioactive waste. The focus of the project is on mutual influences between the HAW and LAW/MAW repositories, which should be constructed separately according to the Safety Regulations (Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, BMU, 2020). A second point of emphasis is on processes that could result from the disposal of small amounts of LAW/MAW within the HAW repository. The analyses carried out for each of the potential host rocks clay rock,
rock salt and crystalline rock as well as for a combination of clay rock
above crystalline rock at a generic site are divided into a qualitative and
a quantitative part. As for the qualitative analyses, all potentially
relevant processes are identified and evaluated as to whether they are
negligible or principally relevant for the exemplary repository
configurations considered and according to the current state of knowledge. With regard to the quantitative analyses, the possible extent of potentially safety-relevant processes is illustrated by means of coupled numerical simulations. Of special interest are the effects of particularly sensitive model approaches and/or parameters and notably of the distances between the HAW and LAW/MAW repositories in the different exemplary repository configurations considered. From the results of the quantitative and qualitative analyses, knowledge
gaps will be identified and the possibility of their reduction by research
and development activities will be discussed. Furthermore, aspects of the
transferability of the results to the German site selection procedure will
be illuminated. At the interdisciplinary research symposium safeND selected preliminary
results of both the qualitative and quantitative analyses will be presented.
Open Source Software Library for Thermo-Hydro-Mechanical Coupled Processes in Python
Authors: Rücker Carsten
Published: November 2021

Abstract. This contributed poster shows the current state of development of a finite
element implementation as part of an open source software library (OSSL) for
the simulation of thermo-hydro-mechanical (THM) coupled processes. The
reliable handling of numerical methods is fundamental for the understanding of
scientific interrelationships and thus, a crucial prerequisite for modeling
THM scenarios, as well as for the understanding and evaluation of preliminary
safety investigations during the site selection process for the storage of
high-level radioactive waste. There are several motivations for developing an
in-house OSSL, which will allow us to:
Build capacity and maintenance within BASE (Federal Office for the Safety of Nuclear Waste Management) regarding issues of the numerical modeling of safety-relevant aspects on the long-term safety analyses specified by the German legislator in the site selection process. Develop a collection of known benchmarks and evaluation examples for the comparison of different software tools, applying a uniform interface to simplify the use of the available highly specialized open source codes. Diversify the testing possibilities regarding the preliminary safety investigations by means of our own, independent modeling software. Document basic THM scenarios for internal or, if necessary, public technical training, e.g., density-driven fluid flow (Fig. 1), convergence in salt, temperature propagation in the repository area, crack development, diffusive or advective mass transport. Ensure transparency and, in principle, might allow for appropriately proven-quality (validated) and documented simulation tools for the public regarding questions about the preliminary safety investigations during the site selection process. The development of the OSSL is mainly based on the scripting language Python,
which allows the necessary flexibility for the diverse fields of application
and at the same time enables maximum transparency for all aspects of the
source code. To ensure the high quality of the software, state of the art
development tools are used (e.g., version control, automated tests, and
documentation generation). Figure 1 shows our preliminary simulation results of the so-called Elder
problem (Elder, 1967), a popular standard benchmark for thermo-hydrogeological
coupling in which fluid motion in a porous medium is driven by buoyancy
forces.
International collaboration in disposal research: comparative modeling of coupled processes in the DECOVALEX project
Authors: Birkholzer Jens T. , Bond Alex
Published: November 2021

Abstract. This presentation gives an overview of an international research collaboration for advancing the understanding and modeling of coupled thermo-hydro-mechanical-chemical (THMC) processes in geological systems. The creation of the international DECOVALEX project, now running for more than 25 years, was motivated by the recognition that prediction of these coupled effects is an essential part of the performance and safety assessment of geologic disposal systems for radioactive waste and spent nuclear fuel. DECOVALEX emphasizes joint analysis and comparative modeling of state-of-the-art field and laboratory experiments, across a range of host rock options and repository designs. Participating research teams are from radioactive waste management organizations, national research institutes, regulatory agencies, universities, and consulting groups, providing a wide range of perspectives and solutions to these complex problems. The presentation provides examples of the research contributions made collectively in past DECOVALEX tasks and also touches on the unique modeling challenges tackled in the ongoing project phase, referred to as DECOVALEX-2023. The current phase comprises 17 partner organizations, about 50 modeling teams, and 7 modeling tasks, which cover a broad portfolio from fundamental studies on gas migration to full-scale in situ heater experiments in different host rocks to performance assessment studies. Together, these examples illustrate that the insight and scientific knowledge gained within the DECOVALEX project would not have been possible if one group had studied these complex THMC modeling challenges alone rather than within a truly collaborative setting.
Knowledge Management in EURAD: the Roadmap
Authors: Beattie Tara , Carbol Paul , Grambow Bernd , Knuuti Tobias , Théodon Louise , Zuidema Piet
Published: November 2021

Abstract. Knowledge management (KM) is a core activity of the European Joint Programme on Radioactive Waste Management (EURAD), which has driven the development of the EURAD Roadmap, a roadmap for the implementation of radioactive waste management (RWM) leading to geological disposal, using the experiences of advanced national and EU programmes. Because these programmes have been developed over more than 40 years and have adopted different technical and strategic approaches to deep geological repository (DGR) development, the roadmap has been structured to capture largely generic best practice in its presentation of programme Phasing and Thematic goals breakdown structure:
5 Phases of Implementation: Initiation, Site Selection, Site Characterization, Construction, and Operations and Closure. For each phase the roadmap explains how activities and existing knowledge are used to fulfil generic safety and implementation goals common across RWM programmes. 7 themes: Programme Management, Predisposal, Engineered Barrier Systems, Geoscience, Design and Optimisation, Siting and Licensing, and Safety Case. Each theme is further elaborated into sub-themes and domains.
The intention of the EURAD roadmap is to provide information and guidance to three primary user groups:
Organisations that are developing or updating their national RWM programmes with the objective of moving towards deep geological disposal of some of their wastes and requiring information on the steps involved; Organisations with advanced RWM and DGR programmes that require an informative training tool for new staff and a means of propagating knowledge across the groups involved in diverse activities; All organisations concerned with identifying potential future gaps in capabilities that could hinder implementation of their DGR programmes in decades to come.
We recognize that there is not a unique route through the roadmap – like any roadmap, it can be used to stimulate consideration of alternative options and can be adapted by each Member State to suit national priorities. Because of its generic nature, the EURAD roadmap will be populated with content that is common to all programmes, creating a basis and strategy for a long-term project of Knowledge Management and Networking in RWM. The current focus is on signposting to existing content and the generation of new content to fill identified gaps for State of Knowledge, State of the Art, Guidance, Training and active Networks or Communities of Practice.
IAEA compiling state of knowledge and developing high level guidance in radioactive waste management
Authors: Mayer Stefan , Robbins Rebecca
Published: November 2021

Abstract. One endeavour central to the International Atomic Energy Agency's (IAEA)
mandate is compiling the international state of knowledge (SoK), supporting
transfer of knowledge and establishing high level guidance for all peaceful
applications of nuclear technologies, including those specific to radioactive waste management (RWM). Building on the current state of experiences and knowledge shared with us from IAEA Member States, we are developing a comprehensive suite of documents on the technologies and solutions having the potential to address RWM needs and steps. This information can be used as a baseline to guide RWM in other countries. In a first approach, the information is compiled and developed in a sequence of documents covering a range of topical domains. These include:
RW: inventory; characterization; use of waste acceptance criteria throughout all RWM steps. RWM steps: a series of handbooks presenting approaches to waste treatment, conditioning and storage; special applications supporting small inventory management needs (e.g. through mobile facilities); considerations specific to management needs of postaccident radioactive waste. Endpoints: introduction to design approaches and disposal concepts; managing site investigations; global compendium of Underground Research Facilities (URF) RD&D; special considerations for small inventory disposal. Programmatic considerations: a generic roadmap to deep geologic repository (DGR) implementation; cost estimation and funding of a disposal programme; stakeholder involvement in disposal. To improve on efficiency and to prove our capacity to compile and transfer an evolving state of knowledge on topics relevant to RWM, the IAEA is building a collection of online interactive contents based on these publications. This online interactive content ultimately aims at containing all our key guidance topics and is intended to provide easier and more rapid access to detailed information. The format would also allow its content to be expanded with descriptions and analyses of topical case studies.
Assessment of Partitioning and Transmutation of High-Level Waste and Hypothetical Implementation Scenarios in Germany
Authors: Frieß Friederike , Liebert Wolfgang , Müllner Nikolaus
Published: November 2021

Abstract. In the context of the search for a deep geological repository for high-level radioactive waste from nuclear energy a preliminary waste treatment is repeatedly called into play by partitioning and transmutation (P&T). Proponents of this approach promise that with P&T, the requirements for and the risks posed by a – then still necessary – repository could be significantly reduced. However, such technological promises have to be prospectively, promptly and publicly reasonably verifiable. Partitioning is reprocessing in which, in addition to separating uranium and plutonium from the fission products, other material streams (for example, the minor actinides) are extracted. In transmutation, radionuclides – especially through nuclear fission – are converted into other nuclides. Thus, conversion of the parent nuclides into nuclides with shorter half-lives, lower radiotoxicity, or into stable nuclides could be achieved. For the assessment of P&T, essential aspects are the current degree of maturity of necessary technologies, the requirements for research and development, technological development risks, the basic feasibility and objective, risks of a hypothetical operation of corresponding plants and the possible effects on nuclear waste disposal. More specifically, on the technological side, it is all about development periods, technical security requirements and licensability, proliferation risks and implementation periods. The presentation of the results of some hypothetical P&T scenarios is intended to help to assess the impacts on radioactive waste present in Germany, necessary facilities and operating periods. Thus, pyro-chemical and hydrochemical separation processes, special transuranic fuels based on mixed oxides (MOX) or uranium-free fuel types and critical fast reactors, subcritical (accelerator-driven) reactors, as well as molten salt reactors, are considered. One difficulty is that the multiple recycling of the transuranics changes the fuel composition. Detailed statements about these changes are only possible with complex simulation calculations and their influence on safe reactor operation. So far, this has not happened on an international scale. In the modelling presented here, an attempt was made to represent the restrictions that the reactor design has on the fuel composition more precisely, at least insofar as the element composition of the fuel remains the same for the duration of the scenario. Conclusions presented from the analysis of the hypothetical scenarios affect, among other things, necessary operating periods and the number of plants and changes achieved in the stock of both transuranics and fission products.
Workshop Safety and Uncertainty
Authors: Hassel Thomas , Mintzlaff Volker , Stahlmann Joachim , Röhlig Klaus-Jürgen , Eckhardt Anne
Published: November 2021

Abstract. Uncertainties have a significant influence on the assessment and
evaluation of the safety of a repository system for high-level
radioactive waste. Significant reasons for uncertainties concerning
the safety barriers of a repository are: Conducting experiments on the long-term behaviour of the repository in real time is impossible due to the long assessment period over which the repository is supposed to ensure safety. The extrapolation of results from time-limited experiments, e.g. on the corrosion of container materials, to other temporal dimensions is associated with uncertainties. Uncertainties also stem from differences between experimental situations, e.g. laboratory experiments, and the real conditions in the repository. The interpretation of empirical results can be ambiguous and therefore associated with uncertainties. The development of future impacts on the barriers can only be predicted to a limited extent. Therefore, the future behaviour of the barriers can only be extrapolated into the future to a limited extent on the basis of experience gained in the past and uncertainties remain. The construction and operation of the repository will disturb its natural environment. The geological environment in which the repository is embedded behaves differently from a natural geological system, which in turn is associated with uncertainties. A major source of uncertainties is also the natural inhomogeneity of the geological barrier, which can only be investigated on a sample basis. During excavation and other construction work underground, unforeseen situations are to be expected, which make it necessary to act situationally. The complexity of the disposal path where decisions are interlinked, creates further uncertainties. Last but not least, it is uncertain what further findings on the safety of the repository will be obtained in the future along the disposal path. For safety studies, especially studies on the long-term safety of repository systems, methods and conventions for dealing with uncertainties have become established internationally. In the site selection process, these methods and conventions are questioned and, if necessary, must be further developed so that they ultimately also convince the interested public and scientists from other disciplines. In the workshop, uncertainties will be examined in particular from the perspectives of a civil engineer and of a materials researcher with introductory presentations. This will be followed by a moderated discussion. The workshop will focus on the preliminary safety investigations; however, the discussion can also refer to later phases of the disposal path. The aim of the discussion is to arrive at a common synthesis: Where have good practices for dealing with uncertainties already been established? Where is there still a need for research and clarification? What needs to be considered in the dialogue with the interested public?
Methods for safety-related weighting and comparative assessment in the site selection process (MABeSt)
Authors: Frieling Gerd , Fischer-Appelt Klaus , Maurer-Rurack Ute , Beuth Thomas , Bracke Guido
Published: November 2021

Abstract. The Federal Office for the Safety of Nuclear Waste Management (BASE) supervises the site selection process in Germany and in particular has the task to review the proposals made by the implementer (Federal Company for Radioactive Waste Disposal, BGE) for determining the siting regions and sites in accordance with §§ 14, 16 and 18 of the German Repository Site Selection Act (StandAG). To determine the siting regions from the sub-areas and the sites from the siting regions, it is likely that safety-related weighting of the results from the application of the geoscientific weighting criteria (§ 24 StandAG) and the application of the preliminary safety investigations (§ 27 StandAG) are necessary. In order to be able to assess and evaluate the proposals of the BGE with respect to the methodological procedure for determining the siting regions and sites, the research project “Methods for safety-related weighting and comparative assessment in the site selection process” (MABeSt) was initiated by BASE. The objective of the research project was to research and explain the state of the art in science and technology (S&T) with respect to safety-oriented weighting and comparative assessment methods and their potential applicability for the selection of siting regions and sites in the site selection process. The status of S&T for safety-oriented weighting and comparative assessment methods was examined and evaluated with respect to site selection procedures for repositories in Germany and abroad (e.g. Switzerland) and also to methodological approaches from other topics (e.g. landfill site selection). The site selection process represents a multicriteria decision problem, which means that methods from the research field of decision theory appear to be suitable. In particular, methods from the multiattribute decision making/aid (MADM) category were identified as suitable and their potential applicability was examined and evaluated. Specific challenges (e.g. data uncertainties, different scales of evaluation criteria) for the relevant procedural steps of the site selection process were taken into account. We present the results and conclusions of the project MABeSt (funding code/4718F13001) carried out by GRS gGmbH and initiated and funded by BASE.
Preliminary safety assessments in the high-level radioactive waste site selection procedure in Germany
Authors: Hoyer Eva-Maria , Kreye Phillip , Lohser Thomas , Rühaak Wolfram
Published: November 2021

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.
Development of a database for the analysis of the disposal system in the representative preliminary safety analysis
Authors: Hoyer Eva-Maria , Müller Paulina , Kreye Phillip , Behrens Christoph , Wengler Marc , Wengorsch Tobias , Rühaak Wolfram
Published: November 2021

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.
Permeability variation in crystalline rocks due to low-grade solution phenomena
Authors: Kilian Rüdiger , Stipp Michael
Published: November 2021

Abstract. Permeability of crystalline rocks depends on parameters such as density and
interconnectivity of fractures and pores. While in pristine crystalline rocks
porosity is usually considered to be low, low-grade solution phenomena such as
the formation of episyenites occur occasionally and may cause a local dramatic
increase in porosity and permeability. These solution phenomena can be
effective in otherwise unaltered rocks and may result in the preferential
removal of certain mineral phases, especially of quartz so that porosities
correspond to the spatial distribution of the previously existing mineral
phase if no subsequent mineralization occurs (e.g., Pennacchioni et al.,
2016). Using light-optical and scanning electron microscopy, X-ray tomography,
micro-XRD, as well as digital image analysis, the differences in connectivity
and hence permeability between, for example, quartz-depleted granite, gneiss,
and schist can be characterized and quantified. We demonstrate that such porosities do not necessarily result in high
permeabilities in an undeformed granodiorite from the Central Gneiss unit of
the Tauern Window (Lago di Neves area, Italy), since former quartz aggregates
are not interconnected due to their relatively late crystallization age and
the preservation of the magmatic fabric; however, in the case of moderate
mylonitic deformation, quartz as rheologically weak phase forms interconnected
aggregates and layers. Its dissolution results in an extremely increased
permeability. Therefore, not only the content and grain size but also the
distribution, shape and alignment of minerals are crucial for rock
permeability and need to be carefully investigated when searching for a final
repository of highly radioactive waste in crystalline rocks. Especially since
local shear zones may form in otherwise undeformed intrusive bodies, a
detailed structural analysis beyond the exclusion of the presence of fractures
is required to mitigate the risk of a long-lasting nuclear waste disposal.
An Open-Access Stress Magnitude Database for Germany
Authors: Morawietz Sophia , Ziegler Moritz , Reiter Karsten ,   the SpannEnD Project Team
Published: November 2021

Abstract. The stress field in the Earth's crust plays a central role in the
site-selection process for a deep geological repository for high-level nuclear
waste. Site selection and construction planning must take into account several
factors that are influenced by the stress state. These include the excavation
damage zone, the hydraulic permeability of the host rock, the self-sealing
capacity, the effects of seismic events and the possible reactivation of
faults as migration pathways for fluids and radionuclides. Likewise, the
initial stress state is of central importance for the long-term studies to
prove site safety over 1 Ma. To obtain a continuous description of the current 3D stress state, 3D
geomechanical numerical models are used. These models have to be calibrated
with data on stress magnitudes to obtain robust predictions. One of the
central goals of the SpannEnD project (Spannungsmodell Endlagerung Deutschland, http://www.spannend-projekt.de, last access: 31 October 2021) was to build the first comprehensive and publicly
accessible stress magnitude database for Germany, including a quality ranking
of the data compiled from different methods. This database is the logical
extension of the database of the World Stress Map project, in which so far
only information on stress orientations and the stress regime has been
compiled systematically. We present this first compilation of stress magnitude
data published and made available by Morawietz et al. (2020). The stress data density is generally low and heterogeneous, so that a model
calibration at the scale of a site model is not possible. Therefore, the main
objective of the SpannEnD project is to develop a 3D geomechanical numerical
model for the whole of Germany. The resulting 3D stress field will provide the
basis for regional and local models in a later phase of the site selection
process. Details on this are presented in three complementary contributions in
this symposium by Reiter et al., Röckel et al. and Ahlers et al. The new
Geology Data Act (Geologie-Datengesetz) now allows access to
considerably more data, which will be incorporated into an update of the
database after assessment according to the defined quality criteria. This
database extension will improve the reliability of the predictions of the
geomechanical models on different spatial scales.
Can we safely go to 200 °C? An integrated approach to assessing impacts to the engineered barrier system in a high-temperature repository
Authors: Birkholzer Jens T. , Zheng Liange , Rutqvist Jonny
Published: November 2021

Abstract. This presentation gives on overview of the complex thermo-hydro-mechanical-chemical (THMC) processes occurring during the disposal of heat-producing high-level radioactive waste in geologic repositories. A specific focus is on the role of compacted bentonite, which is commonly used as an engineered backfill material for emplacement tunnels because of its low permeability, high swelling pressure, and radionuclide retention capacity. Laboratory and field tests integrated with THMC modeling have provided an effective way to deepen our understanding of temperature-related perturbations in the engineered barrier system; however, most of this work has been conducted for maximum temperatures around 100 ∘C. In contrast, some international disposal programs have recently started investigations to understand whether local temperatures in the bentonite of up to 200 ∘C could be tolerated with no significant changes to safety relevant properties. Raising the maximum temperature is attractive for economical and safety reasons but faces the challenge of exposing the bentonite to significant temperature increases. Strong thermal gradients may induce complex moisture transport processes while geochemical processes, such as cementation and perhaps also illitization effects may occur, all of which could strongly affect the bentonite and near-field rock properties. Here, we present initial investigations of repository behavior exposed to strongly elevated temperatures. We will start discussing our current knowledge base for temperature effects in repositories exposed to a maximum temperature of 100 ∘C, based on data and related modeling analysis from a large heater experiment conducted for over 18 years in the Grimsel Test Site in Switzerland. We then show results from coupled THMC simulations of a nuclear waste repository in a clay formation exposed to a maximum temperature of 200 ∘C. We also explore preliminary data from a bench-scale laboratory mock-up experiment, which was designed to represent the strong THMC gradients occurring in a “hot” repository, and we finally touch on a full-scale field heater test to be conducted soon in the Grimsel Test Site underground research laboratory in Switzerland (referred to as HotBENT).
Comparison of Allopurinol And Febuxostat in Asymptomatic Hyperuricemic Patients and their Impact on Serum Creatinine
Authors: Hussain Tafazzul , Sultana Musarrat , Zaidi Syeda Amber , Hasan Syed Saud , Turab Mohsin , Khalid Shamaila
Published: November 2021

Objective: To determine the effect of Allopurinol & Febuxostat for the treatment of hyperuricemic patients & its influence on renal function by measuring serum creatinine level. Study Design & setting: The clinical trial was conducted at Dr. Ruth K M Pfau Civil Hospital, Karachi, during the period of September 2018 to March 2019 Methodology: 60 patients with sUA > 6.8 mg/dl were registered. A detailed history was taken, patient's baseline serum Uric Acid (sUA) & serum Creatinine were measured. Patients were divided into two groups to receive Allopurinol, 300 mg & Febuxostat 80 mg, daily for 90-days. The blood parameters were repeated at day 30 and 90. Results: Group-A (Allopurinol treated patients) baseline uric acid changed from mean 8.79 ± 0.98 mg/dl to 6.40 ± 0.86 mg/dl at day 90. In Group-B (Febuxostat treated patients) sUA baseline mean changed from 8.85 ± 0.97 mg/dl to 5.96 ± 0.68 mg/dl. Mean difference ± SD change of serum uric acid in Group-A was 2.39 ± 1.15 mg/dl and with Group-B it was 2.90 ± 0.87 mg/dl. Mean Serum Creatinine in Group-A changed from 1.54 ± 0.39 mg/dl to mean 1.48 ± 0.40 mg/dl compared with Group-B where it changed from 1.42 ± 0.30 mg/dl to 1.45 ± 0.31 mg/dl at day-90. Mean difference ± SD of serum Creatinine in Group-A was 0.11 ± 0.25 mg/dl & in Group-B it was, 0.03 ± 0.15 mg/dl. The above changes were statistically non-significant with p-value of 0.144. Conclusion: Allopurinol and Febuxostat treatment resulted in improvement of serum Uric Acid levels while maintaining their renal function
Correlation Between Clinical Oral Dryness Score and Salivary Flow Rates in Active and Passive Smokers
Authors: Nigar Seeme , Hassan Sobia , Fahim Sidra , Khalid Ahmed Bin , Salim Faisal
Published: November 2021

Objective: To evaluate the mean clinical oral dryness score (CODs) and salivary flow rate (SFR) in subjects exposed to active and passive smoking. The secondary aim was to determine the correlation between CODs and SFR and potential factors associated with CODs and SFR in our subjects. Study Design and Setting: The clinical observational study was conducted at the Outpatient department of oral diagnosis at Altamash Institute of Dental Medicine, Karachi from Jan 2019-Jul 2019. Methodology: A total of 217 participants of ages 15 – 80years coming for routine dental checkup of either gender were included. A thorough oral examination was performed for all the subjects. A non-stimulated saliva sample was collected from the oral cavity of subjects in a graduated container. The salivary flow rate was noted in ml/min for 5 minutes. Assessment of oral dryness/hypo-salivation was examined through CODs (clinical oral dryness score).The data were analyzed using SPSS software version 23. Results: The mean COD score and SFR were calculated as 1 and 0.42 ml/5min respectively. The Pearson’s correlation between COD score and SFR level was calculated as -0.281 (negative correlation) such as the SFR significantly decreased when the COD score increased (p<0.05). The age, gender, smoking status, betel quid and areca nut consumption showed statistically significant difference in mean COD score and SFR levels (p<0.05). Conclusion: Salivary flow rate was significantly decreased with increase in COD score thus having an implication on oral dryness feeling in these participants.
Is Invasive Mucinous Breast Carcinoma A Rare Variant With Neuroendocrine Differentiation?
Authors: Asghar Ayesha , Shah Aresha Masood
Published: November 2021

We want to bring your attention towards the rare variant of breast cancer hence promoting its early detection and screening. The main advantage of early diagnosis is reduced tumor size without distant dissemination at the initial treatment.
La implicación estadounidense en la guerra contra el Frente Polisario en la década de 1980
Authors: Garí Domingo
Published: November 2021

Con este trabajo se pretende clarificar cuál fue la posición de EE UU en la guerra entre Marruecos y el Sáhara Occidental durante la década de los años ochenta del siglo pasado. La elección de ese momento y el tema se deben a que fueron los años claves para el devenir de la contienda. La implicación de EE UU provocó que el Polisario no pudiese ganar la guerra y constituir su estado independiente. Para llevar a cabo este trabajo se utilizó, principalmente, la documentación de servicios secretos y diplomáticos norteamericanos. Además se usaron trabajos procedentes de distintos investigadores académicos y militares estadounidenses. Se ha hecho un análisis de los textos primarios, y luego han sido confrontados con la literatura disponible que trata el tema. Las conclusiones apuntan a que la implicación norteamericana, y la de muchos de sus socios, fue la causante de una prolongada guerra en el Sáhara Occidental y de que aún permanezca sin resolverse el asunto de los campos de refugiados, así como que la soberanía sobre el territorio siga estando en disputa. La gran ayuda recibida por el reino de Marruecos no fue suficiente para que Hasán II pudiese alzarse con la victoria militar.
Reflection on Criticisms of Critical Geopolitics
Authors: Toal Gerard
Published: November 2021

The book Critical Geopolitics: The Politics of Writing Global Space was first published twenty-five years ago. In this article, I briefly discuss the geopolitical and intellectual sources of inspiration for the development Critical Geopolitics as a distinctive approach within Anglo-American political geography. In doing so, I distinguish it from other concurrent critical approached to International Relations and the world-system within English-speaking Geography at this time. Thereafter I consider four lines of critique of Critical Geopolitics. The first is the argument that the approach is too political. A subsidiary argument considers its relationship to violence. The second is the argument that it is neglects embodiment and everyday life and that, consequently, a Feminist Geopolitics is needed as a necessary corrective. The third is that claim that the approach is too textual and operates with a flawed conception of discourse, one that neglects practice. The fourth critique is that Critical Geopolitics has an undeveloped conception of materiality and neglects more-than-human agency. In discuss these criticisms, I make an argument for a continuity of concern with latent catastrophism in Critical Geopolitics from the danger of nuclear war in the mid-nineteen eighties to the climate emergency of today.
Lymphadenectomy for oncogynecological pathology: evaluation of lymph cyst formation and detection of metastases depending on the number of lymph nodes removed
Authors: Saevets V. V. , Semenov Yu. A. , Muhin A. A. , Taratonov A. V. , Ivahno M. N. , Shmidt A. V.
Published: November 2021

Introduction. Lymphadenectomy in gynecological oncology allows performing adequate surgical staging, determining the need for adjuvant therapy, and reducing the risk of disease recurrence. An increase in the volume of lymphadenectomy leads to an increase in the incidence of postoperative complications — the formation of lymphatic cysts. There are no clear recommendations on the required number of removed lymph nodes in order to identify their metastatic lesions. The aim of the study was to study the possible dependence of the number of removed lymph nodes and the formation of lymphatic cysts. Materials and methods. A retrospective study of 219 patients after surgical treatment from 2020 to 2021 was carried out on the basis of GBUZ Chelyabinsk Regional Center of Oncology and Nuclear Medicine. The study included cases of stage I-IV uterine cancer of all histological types, which underwent radical hysterectomy with bilateral pelvic or bilateral pelvic and paraaortic lymphadenectomy; cases of cervical cancer stage IA1-IIA disease after radical hysterectomy II-III type according to the classification of M.S. Piver, F. Rutledge (1974) with performing bilateral pelvic lymphadectomy. Statistical processing of the results was carried out. Results. The percentage of complications (lymphatic cysts) in the cervical cancer group was 2.06% (N = 2), in the uterine body cancer group 1.72 (N = 2). There was no statistically significant relationship between the removed lymph nodes and their metastatic lesions. Removing more than 27 lymph nodes is a risk factor for developing lymphatic cysts. Discussion. Lymphadenectomy allows for adequate surgical staging and reduces the risk of disease recurrence. Complicated lymphatic cysts occur in 0.9-34% of cases, which was reflected in our study, but the percentage of these complications is quite low. Conclusion. The increase in the volume of lymphadenectomy (removal of more lymph nodes) is justified by the desire for accuracy in the surgical staging of the tumor process. Despite this, there is a risk of complications after lymphadenectomy — the formation of lymphatic cysts that occurs when 27 or more lymph nodes are removed.
Risk factors for ischemic stroke. The role of vitamin D
Authors: Kicherova O. A. , Rejhert L. I. , Ahmetianov M. A.
Published: November 2021

Introduction.The prevalence of cerebral vascular diseases is steadily increasing worldwide. Cerebral stroke represents the most serious of them, being one of the leading causes of mortality and disability of the population. Reduction of morbidity and mortality from stroke can be achieved by improving preventive measures aimed at the correction of risk factors. The review presents domestic and foreign literature data on the risk factors of ischemic stroke and the system of primary prevention of acute ischemic brain lesions.Materials and methods.Data from eLibrary, MedLine, Scopus, Springerlink, and the scientific electronic library «Cyberleninka» were analyzed.Results and Discussion.The authors give an overview of pathological conditions that can lead to the development of cerebral vascular accident. Methods of primary prevention of ischemic stroke are considered in accordance with the European guidelines on stroke management. Current views on the correction of modifiable risk factors (arterial hypertension, diabetes mellitus, hyperlipidemia, heart and vascular pathology, etc.) are presented. Recommendations on lifestyle and body weight reduction are given. In addition to the well-known information, the authors present the data of new studies on the role of vitamin D in the ischemic cascade and consider the possible pathogenetic mechanisms of this effect. The review also provides information on the association of vitamin D deficiency with other pathological conditions that are the causes of ischemic stroke and the effect of vitamin D on the volume of ischemic lesions, the severity of the outcome and the risks of repeated vascular accidents.Conclusion.The study of risk factors for ischemic stroke and the development of primary prevention methods is one of the priority areas of modern neurology, since it will improve the system of care for patients with cerebrovascular disease.