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Date submitted2022-10-29
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Date accepted2023-10-25
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Date published2024-04-25
Assessment of rock massif sustainability in the area of the underground research laboratory (Nizhnekanskii Massif, Enisei site)
The study presents the results of the research on geodynamic and geological conditions of the Enisei site (Krasnoyarsk Krai), chosen for the construction of an underground research laboratory. The laboratory is being built at a depth of 500 m to assess the suitability of the rock mass for burying high-level radioactive waste. The rocks consist of weakly fractured gneisses, granites, and dikes of metadolerites. Field observations were conducted on bedrock outcrops. They included the determination of rock mass quality indicators, measurement of rock fracturing, and a rating classification of stability using N.Barton's method. GNSS observations were also made to monitor surface deformations. These data were used to develop a three-dimensional structural model, including lithology, fault disruptions, intrusive bodies, elastic-strength properties of rocks, and the sizes of zones influenced by faulting. It will serve as a basis for boundary conditions and the construction of three-dimensional variational models of stress-strain states, identifying zones of concentration of hazardous stresses, and planning in situ geomechanical experiments in underground mines of the laboratory. The obtained values of the modified QR index for the main types of rocks allowed their classification as stable and moderately stable, corresponding to strong and very strong rocks on Barton's scale and the massif rating according to geomechanical classification.
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Date submitted2022-01-24
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Date accepted2022-04-26
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Date published2023-04-25
Forecast of radionuclide migration in groundwater of the zone affected by construction drainage at the Leningrad NPP-2
The distribution of natural (at the level of global background) and technogenic radionuclides in groundwater of the industrial zone in Sosnovy Bor town, where several nuclear power facilities are operating, was analyzed. The main technogenic radionuclides recorded in groundwater samples are cesium ( 137 Cs), strontium ( 90 Sr), and tritium isotopes. The first two aquifers from the surface are subject to contamination: the Quaternary and the upper zone of the Lomonosov aquifer. Based on extensive material on the engineering and geological studies of the work area, a 3D geological model and hydrodynamic and geomigration models of the industrial zone were constructed. By means of modeling, the extent and nature of changes in hydrogeological conditions of area resulting from the construction and operational drainage of the new stage of the Leningrad Nuclear Power Plant (LNPP-2) were determined. The “historical” halo of radioactive contamination of groundwater forming (1970-1990) at the site adjacent to the NPP, where the storage facility of low- and medium-level radioactive waste is located, falls into the zone of influence. Interpretation of monitoring data allowed obtaining the migration parameters for predictive estimates. Modeling has shown that during the time of the LNPP-2 operation there was no intake of contaminated water by the drainage system of the new power plant.
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Date submitted2021-03-16
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Date accepted2021-07-27
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Date published2021-10-21
Allocation of a deep-lying brine aquifer in the rocks of a chemogenic section based on the data of geophysical well logging and 2D seismic exploration
Advancement in the production of potassium fertilizers is an important strategic task of Russian agricultural industry. Given annually growing production rates, the reserves of discovered potassium-magnesium salt deposits are noticeably decreasing, which creates the need to ensure stable replenishment of the resource base through both the discovery of new deposits and the exploitation of deep-lying production horizons of the deposits that are already under development. In most cases, deposits of potassium-magnesium salts are developed by underground mining. The main problem for any salt deposit is water. Dry salt workings do not require any additional reinforcement and can easily withstand rock pressure, but with an inflow of water they begin to collapse intensively – hence, special attention is paid to mine waterproofing. Determination of spatial location, physical and mechanical properties of the aquifer and water-blocking stratum in the geological section represent an important stage in the exploration of a salt deposit. The results of these studies allow to validate an optimal system of deposit development that will minimize environmental and economic risks. On the territory of Russia, there is a deposit of potassium-magnesium salts with a unique geological structure – its production horizon lies at a considerable depth and is capped by a regional aquifer, which imposes significant limitations on the development process. To estimate parameters of the studied object, we analyzed the data from CDP seismic reflection survey and a suite of methods of radioactive and acoustic well logging, supplemented with high-frequency induction logging isoparametric sounding (VIKIZ) data. As a result of performed analysis, we identified location of the water-bearing stratum, estimated average thickness of the aquifers and possible water-blocking strata. Based on research results, we proposed methods for increasing operational reliability of the main shaft in the designed mine that will minimize the risks of water breakthrough into the mine shaft.
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Date submitted2019-02-01
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Date accepted2019-09-16
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Date published2020-02-25
Priority parameters of physical processes in a rock mass when determining the safety of radioactive waste disposal
- Authors:
- V. S. Gupalo
Consideration of geodynamic, hydrogeochemical, erosion and other quantitative characteristics describing evolutionary processes in a rock mass is carried out when choosing a geological formation for the disposal of radioactive waste. However, the role of various process parameters is not equal for safety ensuring and additional percentages of measurement accuracy are far from always being of fundamental importance. This makes it necessary to identify various types of indicators of the geological environment that determine the safety of radioactive waste disposal for their detailed study in the conditions of the burial site. An approach is proposed to determine the priority indicators of physical processes in the rock mass that determine the safety of disposal of various types of radio active waste and require increased attention (accuracy, frequency of measurements) when determining in - situ conditions. To identify such factors, we used the sensitivity analysis method that is a system change in the limits of variable values during securty modeling in order to assess their impact on the final result and determine the role of various physical processes in ensuring safety.
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Date submitted2016-08-30
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Date accepted2016-10-30
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Date published2017-02-22
Gas-dynamic processes affecting coal mine radon hazard
- Authors:
- V. I. Efimov
- A. B. Zhabin
- G. V. Stas
The paper focuses on vertical migration of radon in surrounding rocks described by Fick's first law as well as by the continuity equation for diffusion flow, with allowance for sorption and radioactive decay processes. Taking into account special characteristics of vertical radon diffusion, the process can be considered stable. It is demonstrated that for productive areas it is feasible to consider one-dimensional convective diffusion, as diffusive transport of radon by the air of productive areas occurs at steady-state conditions. Normally the factor of radon emissions prevails if atmospheric pressure is constant. Amount of air, calculated using this factor, by 20-30 % exceeds the one needed to dilute carbon dioxide to maximum allowed concentration (MAC).
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Date submitted2015-10-12
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Date accepted2015-12-26
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Date published2016-08-22
Use of various types of carbon-containing raw materials to produce thermal energy
- Authors:
- V. B. Kuskov
- V. Yu. Bazhin
Many types of carbon-containing organic compounds and all possible carbon-containing products or wastes in low demand can be used to produce thermal energy. A technology has been developed for producing highly flammable briquettes on the basis of bituminous coal. These briquettes have a special incendiary layer. It is easily ignites from low energy heat sources (e.g. matches), and then flame spreads to the rest of briquette. Use of coal slacks and paper wastes as carbon-containing components playing the role of binders provides an opportunity to get a fuel briquette easy in terms of production and plain in composition while at the same time dispose of coal and paper wastes. Such briquettes may also have a special incendiary layer. Technology for fuel briquettes production from wood and slate wastes employed no binding agents, as wood products acted as binders. Thus technologies have been developed to produce fuel briquettes from various carbon-containing materials in low demand. The briquettes are intended for household boilers, fireplaces, different ovens in order to cook food, heat residential and utility premises, cabins, etc.
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Date submitted2008-10-12
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Date accepted2008-12-17
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Date published2009-12-11
Principles of development of geological engineering and geological criteria for safe burial of low radioactive wastes in lower cambrian blue clays in the Leningrad region
- Authors:
- R. E. Dashko
It is noticed that the chosen territory for nuclear-waste disposal in Lower Cambrian clay massif nearby Koporje of Leningrad region takes place in a tectonic zone. Lower Cambrian clays are considered as the block-fractured rock mass having a depth zone structure. The long radioactive irradiation of dark blue clays has led to transformation of their structure, physical-chemical and physical-mechanical properties, and also to activization of microbial activity. Nine criteria to the geoenvironmental and engineering geological characteristics allowing in a complex to estimate safety and reliability of a nuclear-waste disposal in clay formations on an example of dark blue clays are suggested.