Geodynamic aspects of high-level radioactive waste disposal: a case-study of Nizhnekansky massif

2021 ◽  
pp. 108-112
Author(s):  
V. N. Tatarinov ◽  
V. N. Morozov ◽  
A. I. Manevich ◽  
E. N. Kamnev

This article describes the methodological aspects and some results of the assessment and prediction of the geodynamic stability of the geological environment as applied to the problem of ensuring the safety of underground isolation of high-level radioactive waste (HLRW) in the geological formations of the Nizhnekansky massif, Krasnoyarsk Region. For this, the authors introduced a basic concept of the stability of the geological environment. Based on instrumental observations, mathematical models, system analysis of geospatial data, the ranking of structural tectonic blocks according to the degree of stability and the geodynamic zoning of the northern part of the Nizhnekansky massif were implemented. To assess the stability, the authors used geological data, a digital elevation model, the results of the interpretation of geophysical fields and geodetic observations. It is shown that the stability of the blocks differs significantly according to kinematic parameters. Geodetic observations based on GPS/GLONASS satellite systems, carried out in 2010-2019, made it possible to obtain for the first time information on the rates of horizontal movements of the lithosphere and their cyclicity for the region located in the zone of force interaction of the largest tectonic structures, namely, Siberian platform, West Siberian plate and the Altai-Sayan Orogen. The maximum speeds were recorded for points located in the zone of dynamic influence of the Muratovsky and Pravoberezhny faults. The energy concentration criteria as the fracturability characteristics of structural rock blocks are proposed for the stress–strain analysis of rock mass. To substantiate the long-term geodynamic safety of deep disposals of HLRW of the 1st and 2nd classes, the authors developed a program for the long-term observations of differentiated movements in the earth’s crust and seismic activity for 2021–2026 in an underground research laboratory. The study was carried out under the state contract between the Geophysical Center of the Russian Academy of Sciences and the Ministry of Science and Higher Education of the Russian Federation.

2003 ◽  
pp. 203-208
Author(s):  
Hideo KOMINE ◽  
Nobuhide OGATA ◽  
Akira NAKASHIMA ◽  
Hajime TAKAO ◽  
Hiroyoshi UEDA ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yong-Gui Chen ◽  
Xue-Min Liu ◽  
Xiang Mu ◽  
Wei-Min Ye ◽  
Yu-Jun Cui ◽  
...  

In China, Gaomiaozi (GMZ) bentonite serves as a feasible buffer material in the high-level radioactive waste (HLW) repository, while its thermal conductivity is seen as a crucial parameter for the safety running of the HLW disposal. Due to the tremendous amount of heat released by such waste, the thermal conductivity of the buffer material is a crucial parameter for the safety running of the high-level radioactive waste disposal. For the purpose of improving its thermal conductivity, this research used the graphene oxide (GO) to modify the pure bentonite and then the nanocarbon-based bentonite (GO-GMZ) was obtained chemically. The thermal conductivity of this modified soil has been measured and investigated under various conditions in this study: the GO content, dry density, and water content. Researches confirm that the thermal conductivity of the modified bentonite is codetermined by the three conditions mentioned above, namely, the value of GO content, dry density, and water content. Besides, the study proposes an improved geometric mean model based on the special condition to predict the thermal conductivity of the compacted specimen; moreover, the calculated values are also compared with the experimental data.


2021 ◽  
Author(s):  
Marc Wengler ◽  
Astrid Göbel ◽  
Eva-Maria Hoyer ◽  
Axel Liebscher ◽  
Sönke Reiche ◽  
...  

<p>According to the 'Act on the Organizational Restructuring in the Field of Radioactive Waste Disposal' the BGE was established in 2016. The amended 'Repository Site Selection Act' (StandAG) came into force in July 2017 and forms the base for the site selection by clearly defining the procedure. According to the StandAG the BGE implements the participative, science-based, transparent, self-questioning and learning procedure with the overarching aim to identify the site for a high-level radioactive waste (HLW) repository in a deep geological formation with best possible safety conditions for a period of one million years.</p><p>The German site selection procedure consists of three phases, of which Phase 1 is divided into two steps. Starting with a blanc map of Germany, the BGE completed Step 1 in September 2020 and identified 90 individual sub-areas that provide favorable geological conditions for the safe disposal of HLW in the legally considered host rocks; rock salt, clay and crystalline rock. Based on the results of Step 1, the on-going Step 2 will narrow down these sub-areas to siting regions for surface exploration within Phase 2 (§ 14 StandAG). Central to the siting process are representative (Phase 1), evolved (Phase 2) and comprehensive (Phase 3) preliminary safety assessments according to § 27 StandAG.</p><p>The ordinances on 'Safety Requirements' and 'Preliminary Safety Assessments' for the disposal of high-level radioactive waste from October 2020 regulate the implementation of the preliminary safety assessments within the different phases of the siting process. Section 2 of the 'Safety Requirements' ordinance provides requirements to evaluate the long-term safety of the repository system; amongst others, it states that all potential effects that may affect the long-term safety of the repository system need to be systematically identified, described and evaluated as “expected” or “divergent” evolutions. Additionally, the ordinance on 'Preliminary Safety Assessments' states in § 7, amongst others, that the geoscientific long-term prediction is a tool to identify and to evaluate geogenic processes and to infer “expected” and “divergent” evolutions from those. Hence, considering the time period of one million years for the safe disposal of the HLW and the legal requirements, it is essential to include long-term climate evolution in the German site selection process to evaluate the impact of various climate-related scenarios on the safety of the whole repository system.</p><p>To better understand and evaluate the influence of climate-related processes on the long-term safety of a HLW repository, climate-related research will be a part of the BGE research agenda. Potential research needs may address i) processes occurring on glacial – interglacial timescales (e.g. the inception of the next glaciation, formation and depth of permafrost, glacial troughs, sub-glacial channels, sea-level rise, orbital forcing) and their future evolutions, ii) effects on the host rocks and the barrier system(s) as well as iii) the uncertainties related to these effects but also to general climate models and predictions.</p>


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