This paper presents a neutronics design of a 10 MW ordered-pebble-bed fluoride-salt-cooled high-temperature experimental reactor. Through delicate layout, a core with ordered arranged pebble bed can be formed,which ca...This paper presents a neutronics design of a 10 MW ordered-pebble-bed fluoride-salt-cooled high-temperature experimental reactor. Through delicate layout, a core with ordered arranged pebble bed can be formed,which can keep core stability and meet the space requirements for thermal hydraulics and neutronics measurements.Overall, objectives of the core include inherent safety and sufficient excess reactivity providing 120 effective full power days for experiments. Considering the requirements above, the reactive control system is designed to consist of 16 control rods distributed in the graphite reflector. Combining the large control rods worth about 18000–20000 pcm, molten salt drain supplementary means(-6980 to -3651 pcm) and negative temperature coefficient(-6.32 to -3.80 pcm/K) feedback of the whole core, the reactor can realize sufficient shutdown margin and safety under steady state. Besides, some main physical properties, such as reactivity control, neutron spectrum and flux, power density distribution, and reactivity coefficient,have been calculated and analyzed in this study. In addition, some special problems in molten salt coolant are also considered, including ~6Li depletion and tritium production.展开更多
Shale oil of the Qingshankou Formation of the Gulong Sag,the northern Songliao Basin,represents the first attempt at large-scale development of pure-shale-type shale oil in China.By integrating the multiscale refined ...Shale oil of the Qingshankou Formation of the Gulong Sag,the northern Songliao Basin,represents the first attempt at large-scale development of pure-shale-type shale oil in China.By integrating the multiscale refined reservoir characterization with macro-micro-scale mechanical testing,it is clarified that the Gulong shale is characterized by high clay mineral content,high rock plasticity,highly-developed bedding,and prominent mechanical anisotropy.A three-dimensional(3D)fracture propagation model of hydraulic fracturing was built for the Gulong shale,which fully captures the hydraulic fracture distribution pattern affected by the high bedding density,in-situ stress,and fracturing treatment parameters.Our research showed that due to influences of bedding,hydraulic fracturing in the Gulong shale forms a complex fracture morphology featuring the main fracture with multiple perpendicular branches that have different lengths(like the outdoor directional TV antenna);however,the vertical propagation of fractures is inhibited,and the fracture height is commonly less than 10 m.The limited stimulated reservoir volume(SRV)is the main problem facing the fracturing stimulation of the Gulong shale oil.Bedding density has vital effects on fracture morphology,so case-specific fracturing designs shall be developed for shale intervals with different bedding development degrees.For reservoirs with welldeveloped bedding,it is suggested to properly increase the perforation cluster spacing and raise the volume and proportions of viscous fluids of the pad,so as to effectively promote vertical fracture propagation and improve reservoir stimulation performance.This study integrates multi-scale fine reservoir characterization and macro-micro-scale mechanical testing,as well as the construction and numerical simulation of hydraulic fracturing models for high-density layered shale reservoirs,providing a new approach and methodological framework for the fracturing research of high-density layered shale reservoirs.展开更多
基金supported by the Chinese Academy of Sciences TMSR Strategic Pioneer Science and Technology Project(No.XDA02010000)Thorium uranium fuel cycle characteristics and key problem research Project(No.QYZDY-SSW-JSC016)
文摘This paper presents a neutronics design of a 10 MW ordered-pebble-bed fluoride-salt-cooled high-temperature experimental reactor. Through delicate layout, a core with ordered arranged pebble bed can be formed,which can keep core stability and meet the space requirements for thermal hydraulics and neutronics measurements.Overall, objectives of the core include inherent safety and sufficient excess reactivity providing 120 effective full power days for experiments. Considering the requirements above, the reactive control system is designed to consist of 16 control rods distributed in the graphite reflector. Combining the large control rods worth about 18000–20000 pcm, molten salt drain supplementary means(-6980 to -3651 pcm) and negative temperature coefficient(-6.32 to -3.80 pcm/K) feedback of the whole core, the reactor can realize sufficient shutdown margin and safety under steady state. Besides, some main physical properties, such as reactivity control, neutron spectrum and flux, power density distribution, and reactivity coefficient,have been calculated and analyzed in this study. In addition, some special problems in molten salt coolant are also considered, including ~6Li depletion and tritium production.
基金supported by the General Program of National Natural Science Foundation of China(No.52274058)the“Enlisting and Leading”Science and Technology Project of Heilongjiang Province(No.RIPED-2022-JS-1740 and No.RIPED-2022JS-1853)the Central Program of Basic Science of the National Natural Science Foundation of China(No.72088101)。
文摘Shale oil of the Qingshankou Formation of the Gulong Sag,the northern Songliao Basin,represents the first attempt at large-scale development of pure-shale-type shale oil in China.By integrating the multiscale refined reservoir characterization with macro-micro-scale mechanical testing,it is clarified that the Gulong shale is characterized by high clay mineral content,high rock plasticity,highly-developed bedding,and prominent mechanical anisotropy.A three-dimensional(3D)fracture propagation model of hydraulic fracturing was built for the Gulong shale,which fully captures the hydraulic fracture distribution pattern affected by the high bedding density,in-situ stress,and fracturing treatment parameters.Our research showed that due to influences of bedding,hydraulic fracturing in the Gulong shale forms a complex fracture morphology featuring the main fracture with multiple perpendicular branches that have different lengths(like the outdoor directional TV antenna);however,the vertical propagation of fractures is inhibited,and the fracture height is commonly less than 10 m.The limited stimulated reservoir volume(SRV)is the main problem facing the fracturing stimulation of the Gulong shale oil.Bedding density has vital effects on fracture morphology,so case-specific fracturing designs shall be developed for shale intervals with different bedding development degrees.For reservoirs with welldeveloped bedding,it is suggested to properly increase the perforation cluster spacing and raise the volume and proportions of viscous fluids of the pad,so as to effectively promote vertical fracture propagation and improve reservoir stimulation performance.This study integrates multi-scale fine reservoir characterization and macro-micro-scale mechanical testing,as well as the construction and numerical simulation of hydraulic fracturing models for high-density layered shale reservoirs,providing a new approach and methodological framework for the fracturing research of high-density layered shale reservoirs.
