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China Energy Reserve and Chemicals Group is exploring the possibility of importing LNG from the US via ISO containers loaded from the West Coast. Japan is bringing its nuclear reactors back on line following the suspension of operations at all reactors after the 2011 Fukushima accident. As the reactors return to full operation, the increase in nuclear generation is likely to displace generation from fossil sources, in particular natural gas.
Asian spot prices for LNG took a dive to multiyear lows, feeling the pressure of the lack of demand. Holders of previously agreed upon long-term buyer contracts seek renegotiation. The decision follows a previous $10-billion investment in LNG the country made in 2017. While that investment focused on outside energy supply sources, this one will be used to develop infrastructure in Southeast Asia and the Indian subcontinent. The Japanese operator will submit a development plan to the Indonesian government within the next few weeks, with FID for the $20-billion project coming around 2022.
This standard presents accepted methods and practices regarding the use of cathodic protection (CP) for the control of external corrosion on buried or submerged carbon steel, stainless steel, gray cast iron, ductile cast iron, copper, and aluminum piping systems at nuclear power plants. This standard may be useful at facilities other than nuclear power plants that contain complex networks of buried or submerged piping, which may be composed of more than one material and may or may not be grounded.
This standard addresses the design of CP systems in nuclear power plants for new piping systems and existing coated and uncoated piping systems. For each type of system, information is provided concerning the effects of grounding of the piping system on the design of the CP system. It also introduces design concepts for new piping systems that will assist in the design, operation, testing, or maintenance of a CP system.
This standard also presents accepted methods and practices for the installation, operation (including acceptance criteria), testing, and maintenance of CP systems in nuclear power plants. It presents criteria and procedures that may be used to determine the conditions under which a pipe or piping system need not be cathodically protected.
The primary NACE standard addressing cathodic protection (CP) of buried and submerged onshore piping systems is SP0169, “Control of External Corrosion on Underground or Submerged Metallic Piping Systems.”1 While the scope of SP0169 is primarily intended for onshore buried and submerged metallic piping systems, its major users include the oil and gas industry. Oil and gas transmission pipelines share certain characteristics which affect the design, installation, operation, and maintenance of CP systems.
The decision follows a previous $10-billion investment in LNG the country made in 2017. While that investment focused on outside energy supply sources, this one will be used to develop infrastructure in Southeast Asia and the Indian subcontinent. The Japanese operator will submit a development plan to the Indonesian government within the next few weeks, with FID for the $20-billion project coming around 2022. Japan is bringing its nuclear reactors back on line following the suspension of operations at all reactors after the 2011 Fukushima accident. As the reactors return to full operation, the increase in nuclear generation is likely to displace generation from fossil sources, in particular natural gas.
The PDF file of this paper is in Russian.
A study of world experience in other industries, such as aviation, military and nuclear industry, has shown that non-trivial engineering tasks of creating complex systems require working at the intersection of several technical disciplines. In 1957, G. Goode and R. Macol emphasized the achievements of mathematical science in the system method of designing technical equipment. In their view, the main problem for design engineers is the ever-increasing complexity of systems that cannot be implemented by scaling small system implementation tools. The authors proposed to train specialists with a wide range of disciplines, as well as to form design teams for the implementation of complex projects. The development of system engineering in Russia began in the 1960s under the name of system engineering, the emergence of which was caused by the problems of building complex military systems. A new stage of the development of domestic system engineering came at the beginning of 2010. Problems arising from complex projects have led to a call for systemic engineering practices. This article focuses on describing the role of the integrator in the project and the requirements for its competencies based on international experience. The formation of a philosophy of system thinking and the introduction of system engineering in the oil and gas industry will improve the efficiency of asset management throughout the life cycle. Creating a new paradigm of thinking and approach to engineering activities inevitably leads to the training of new format specialists who will perform an integrating function that will allow to control safety, technology and project efficiency.
В новой стратегии ПАО «Газпром нефть» ставит перед собой задачу к 2030 г. стать ориентиром для других компаний отрасли в мире по безопасности, эффективности и технологичности. Изучение мирового опыта в других отраслях, таких как авиастроение, военная и атомная промышленность, показало, что для решения нетривиальных инженерных задач по созданию сложных систем необходимо работать на стыке нескольких технических дисциплин. В 1957 г. Г. Гуд и Р. Макол предложили делать акцент на достижения математической науки в системном методе проектирования технического оборудования. В качестве основной проблемы для инженеров-проектировщиков они выделили постоянно возрастающую сложность систем, которые невозможно реализовать с помощью масштабирования инструментов реализации малых систем. Г. Гуд и Р. Макол предложили при подготовке специалистов использовать широкий охват различных дисциплин, а также формировать проектные команды для воплощения сложных проектов. Развитие системной инженерии в России начинает свой отсчет с 60-х годов ХХ века (системотехника), появление которой было обусловлено проблемами построения сложных систем военного назначения. Новый этап развития отечественной системной инженерии пришелся на начало 2010 г. Проблемы, возникающие при реализации сложных проектов, заставили обратиться к практикам системной инженерии. В статье рассмотрена роль инженера-интегратора в составе рабочей группы проекта и требованиям, которые предъявляются к его компетенциям, сформулированным на основе международного опыта. Формирование философии системного мышления и внедрение системного инжиниринга в процессы нефтегазовой отрасли позволят повысить эффективность управления активами на протяжении всего жизненного цикла. Создание новой парадигмы мышления и подхода к осуществлению инженерной деятельности даст возможность подготовить специалистов нового формата, которые будут выполнять интегрирующую функцию.
Fracture distribution in bedrock has a great influence on the groundwater flow, whose characteristics should be understood for resource exploration and deep geological repository and so on. Previous studies have been attempting to grasp the hydraulic characteristics on a local scale using boreholes and so on. However, it is considered to be difficult to grasp the hydraulic permeability without drillings. In this study, we tried to estimate the permeability of rocks in deep underground from physical property values like resistivity and Young's modulus in order to grasp macroscopic hydraulic characteristics of rock including fracture. The validity of the present estimation method was examined, by comparing this estimated value with the measured value. The resistivity and Young's modulus of exposed granitic rock mass at depth of 300-500m were measured in the underground research gallery at the Mizunami Underground Research Laboratory, Japan Atomic Energy Agency in 2017. We estimated the permeability using a rock physics model. The permeability was also measured in 2015 along the same gallery, therefore compared with the estimated permeability from our geophysical measurements.
Nuclear power plants are used in many countries. But disposal of radioactive waste is an issue. It is said that geological disposal is most practical method to solve the issue. But his method has a leakage risk radioactive waste by groundwater flow. So, it is necessary to grasp the hydraulic characteristics for evaluation of leakage risk of radioactive material by groundwater flow. However, it is considered to be difficult to grasp the hydraulic permeability without drillings. In this study, we tried to estimate the permeability of rocks from measured physical properties in Mizunami Underground Research Laboratory. And we compared measured permeability and estimated one and discussed its relevance.
We measured exposed bedrock walls along the research tunnels (depth 300 m, 500 m) of the Mizunami underground research labolatory of the Japan Atomic Energy Agency, located in Mizunami-city, Gifu Prefecture. In this area, a lot of logging data have been published and the fracture distribution in the gallery was also examined in detail (e.g., Ishibashi et al., 2016). Furthermore, permeability of the rock wall was measured in 2015 (Sato, 2015). In this study, we measured resistivity using a small electric surveying device (4-pole method with electrode interval of about 10 cm) and the Young's modulus using a Schmidt-lock hammer. The measured data are shown Fig.1.
Liu, Liyuan (School of Civil and Resource Engineering) | Ji, Hongguang (School of Civil and Resource Engineering) | Zhi, Sheng (EMS Energy Institute and G3 Center) | Wang, Tao (School of Civil and Resource Engineering)
The study of alterations in rock mechanical properties as a function of thermal damage is relevant to various engineering applications, such as nuclear waste repository, underground coal gasification, dry fracture shale system, and geothermal energy extraction. The mechanical behavior of reservoir rock is significantly influenced by the elevated temperatures, since the status of micro-structure of the rock mass is controlled by thermal expansion, newly-generated micro-cracks, dilation of existing micro-cracks, and various mineralogical alterations. Rock yield strength is generally positive with the elastic modulus, cohesive strength and friction angle, while it decreases with temperature increasing.
The following defines a novel thermal-mechanical-damage coupled model accommodating the interaction of thermal conductivity, thermal-induced deformation and rock mechanical deformation and damage to define the changes in rock thermal and mechanical properties during thermal treatment. Importantly, we developed a dual-damage constitutive model for elastic modulus and strength respectively, to solve the problem of the non-synchronous changes in peak strain and peak strength, which is induced by its thermal damage. The proposed model is validated by the laboratory data.
The results indicate that thermal-induced damage has a significant effect on rock physical and mechanical properties-increases rock porosity and permeability and decreases rock elastic modulus and strength. Furthermore, it is confirmed that the thermal-induced damage is dominated by tensile damage of rock during the thermal expansion. The proposed dual-damage constitutive model better explains the changes of peak strain and peak strength observed in experiments.
Thermal-induced rock damage plays a vital role for various engineering applications, such as nuclear waste repository, underground coal gasification, dry fracture shale system, geothermal energy extraction, and deep mining (Cai and Brown, 2017; Heap et al., 2011; Shao et al., 2015; Shoko et al., 2006; Tsang, 1999). Therefore, it is of great significance to understand alterations of rock mechanical properties induced by thermal damage for the design and safety assessment in deep underground rock engineering.
Quantitative evaluation for the seismic performance of critical facilities, such as nuclear power plants, to earthquake-induced failure of surrounding slopes, are becoming increasingly important as the level of design for earthquake ground motion for nuclear power plants becomes wider. To carry out earthquake response analysis, the Extended Distinct Element Method (EDEM) is considered ideal. EDEM has uncertainties of initial particle arrangement and shear strength parameters of cohesion parameter and dynamic friction coefficient. Therefore, we investigated the uncertainties in EDEM results of failure timing by initial particle arrangements and cohesion parameters. The purpose of this study was to judge whether the uncertainty of dynamic friction coefficient should be considered when the uncertainty of shear strength between particles in EDEM needs to be considered. The final goal of this research is to build rational EDEM approach in in Probabilistic Risk Assessment (PRA) framework by reducing computational time from ignoring parameters which do not influence on analytical results. We conducted fifty numerical simulations from dynamic friction coefficients and compared these results with those of previous studies on the uncertainty of cohesion parameters. Results show that the uncertainty of dynamic friction coefficients has less influence on the numerical simulation results than cohesion parameters. Therefore, the uncertainty of dynamic friction coefficient may be ignored if the coefficient of variation is somewhat small.
After high magnitude earthquakes such as the Great East Japan Earthquake, the level of the design for earthquake ground motion for nuclear power plants has become wider. Therefore, quantitative evaluations of the seismic performance of critical facilities, such as nuclear power plants to earthquake-induced failure of surrounding slopes are becoming increasingly important as a deterministic approach in regulation. Moreover, evaluation of other aspects other than the design -based earthquake ground motion in Probabilistic Risk Assessment (PRA) is important as the voluntary activity by corporation.
The seismic stability of the surrounding slopes is often determined by the Finite Element Method (FEM) based on ground displacement. For example, the CRIEPI recommends a time history nonlinear analysis for evaluating the stability of slopes, including post-earthquake residual displacement, and predicting a failure range when large deformations and displacements occur (Ishimaru, 2017).
One of the important tasks in the on-site fault assessment of nuclear power plants is the estimation of fault displacements and their impact on the safety functions of facilities. Numerical prediction is one of the preferable methods for estimating fault displacements. The author proposes a numerical prediction method for estimating surface fault displacement using the dynamic fault rupture analysis. The proposed method is applied to the 2016 Kumamoto earthquake with surface faulting.
In this study, both primary and secondary faults are considered. For the primary faults, the fault rupture is initiated at a predefined hypocenter, and programmed to propagate outward along the fault plane with specified rupture velocities and stress drops until it is arrested at the edge of the fault plane. The calculation of the surface slip distribution on primary faults was consistent with the measured slip value. In the simulation, surface slip also appeared on the secondary faults. However, the calculated values of the surface slips on the secondary faults were not as consistent with the measured slip values. Therefore, the proposed numerical method is applicable to evaluating the possibility of surface slip on secondary faults. In the simulation, the appearance of the surface slip almost coincided with the occurrence of strong vibrations along the secondary faults.
One of the aftermaths of the 1999 massive earthquakes in Taiwan and Turkey is the growing concerns regarding the potential damage to various infrastructures and buildings caused by surface fault ruptures. Therefore, for the on-site fault assessment of nuclear power plants (NPPs), it is important to estimate the fault displacement and their impact on facility safety functions. Detailed geological surveys showed that important facilities in the NPPs were separated from the primary faults that are a direct extension from the earthquake fault source. Nevertheless, there are several cases of secondary faults beneath or close to these important facilities. Research has explored the activities of such faults. Estimating fault displacement is a crucial issue in on-site fault assessment. Numerical simulation has the potential to provide a reliable estimation of fault displacement.
Water migration is an important issue in sealability of underground radioactive waste disposal (URWD) and is significantly controlled by permeability of rock. Whereas, the permeability of rocks varies with various factors such as stress and temperature. In and around an underground radioactive waste disposal site, the rock stress changes by excavation of caverns for URWD and rock temperature changes by decay heat where the temperature change induces thermal stress. Therefore, water migration should be evaluated considering the effect of stress and temperature. In this regard, a series of triaxial compression tests was carried out under confining pressure between 1 and 14 MPa at 295 K and 353 K, and the permeability under residual strength state was measured. Shikotsu welded tuff, Kimachi sandstone and Inada granite were considered for the experiment to cover wide range of physical properties. The equations for the stress and temperature dependent permeability of fractured rocks were proposed. Fluid inflow was calculated with a 2-D elastic FEM for a simple URWD cavern with or without considering the stress and temperature dependency as an example to show the effect on water inflow. The results showed that water inflow became smaller considering the dependency. This could contribute for optimum design of underground caverns. Several new indices were also correlated with the post-compression permeability to show how well it could be predicted. The effects of temperature became slightly smaller by considering the permeability of fractured rock with the indices than that of average effective stress (AES). Further consideration is needed because the effects of temperature could be seen in the indices-permeability plots and the new indices were almost not effective to improve the approximation for granite.
Water migration is an important factor in sealability of underground radioactive waste disposal (URWD) from the environmental point of view and is significantly controlled by permeability of rock. The permeability of rocks varies with various factors including stress and temperature (Alam et al., 2014 and 2015). The rock stress changes by excavation of caverns for URWD and rock temperature changes by decay heat and the temperature change induces thermal stress. Water migration around URWD should be therefore evaluated considering the effect of stress and temperature. In underground the rock masses are fractured and the state of stress is compressive. In this regard, a series of triaxial compression tests was carried out under confining pressure between 1 and 14 MPa at 295 K and 353 K, and the permeability under residual strength state was measured. The three types of rock (Shikotsu welded tuff, Kimachi sandstone and Inada granite) are considered for the experiment to cover wide range of physical properties of rock. The equations which represent the post-compression permeability by average effective stress and temperature were proposed (Alam et al., 2015).