The aerosolization and diffusion of radioactive materials caused by chemical explosions represent a typical nuclear accident scenario that poses severe radioactive hazards to human health and the environment.This stud...The aerosolization and diffusion of radioactive materials caused by chemical explosions represent a typical nuclear accident scenario that poses severe radioactive hazards to human health and the environment.This study examines the diffusion of plutonium aerosol generated by a chemical explosion within a typical representative underground facility.The state of explosion products following a single-point detonation of explosives was simulated.Subsequently,a numerical simulation of plutonium aerosol diffusion using the discrete phase model(DPM)was conducted based on the outcomes of the chemical explosion simulation.The simulation results indicate that plutonium aerosols diffuse throughout underground facilities after a chemical explosion;small particle size aerosols primarily accumulate in the upper part of the room after the accident;the concentrations of plutonium aerosol in the room and tunnel are significantly higher than those in the other areas;and the temporal variations in aerosol concentration in each area were quantified.Based on the particle concentration distribution and the effective dose computation approach,the study computes the internal irradiation dose received by personnel in seven areas over various time periods post-accident.Recommendations for emergency decision-making were derived from these calculations.These findings provide important theoretical insight and practical engineering application value for understanding the diffusion of radioactive aerosol in confined spaces following chemical explosions and for evaluating personnel radiation dose.展开更多
This study centers on the use of smart technology to improve the lifecycle management of underground facilities.It presents a comprehensive digital solution that addresses the challenges of underground facilities,part...This study centers on the use of smart technology to improve the lifecycle management of underground facilities.It presents a comprehensive digital solution that addresses the challenges of underground facilities,particularly those related to the extensive use of underground space,as well as the requirements for safety,sustainability,and quality of services.The proposed solution emerged from discussions with experts,companies,and cities involved in the design,construction,and management of underground facilities.In this paper,we first discuss the major challenges of underground facilities,then,we present the development of a smart solution to address these challenges.This study demonstrates a promising perspective for the use of smart technology in the optimal management of underground facilities,and paves the way for its implementation.展开更多
Subways,underground logistics systems and underground parking,as the primary facilities types of underground,contribute significantly to the achievement of carbon–neutral cities by moving surface transportation to un...Subways,underground logistics systems and underground parking,as the primary facilities types of underground,contribute significantly to the achievement of carbon–neutral cities by moving surface transportation to underground,thereby releasing surface space for the creation of more urban blue-green space for carbon sink.Therefore,in-depth studies on carbon neutrality strategies as well as reliable layout optimization solutions of these three types of underground facilities are required.This study proposes a spatial layout optimization strategy for carbon neutrality using underground hydrogen storage and geothermal energy for these three types of underground facilities employing a multi-agent system model.First,three spatial layout relationships,competition,coordination,and followership,between five underground facilities that contribute to emission reduction were investigated.Second,the implementation steps for optimizing the spatial layout of underground facilities were determined by defining the behavioral guidelines for spatial environment,underground facility,and synergistic agent.Finally,using the Tianfu New District in Chengdu City,China,as a case study,layouts of underground facilities under three different underground space development scenarios were simulated to verify the model.The findings of this study address the gap in the research on underground spatial facilities and their layout optimization in response to emission reduction.This study provided a significant reference for the study of underground space and underground resources at the planning level to aid in achieving carbon–neutral cities.展开更多
In this study,we numerically investigate the influence of hysteretic stress path behavior on the seal integrity during underground gas storage operations in a depleted reservoir.Our study area is the Honor Rancho Unde...In this study,we numerically investigate the influence of hysteretic stress path behavior on the seal integrity during underground gas storage operations in a depleted reservoir.Our study area is the Honor Rancho Underground Storage Facility in Los Angeles County(California,USA),which was converted into an underground gas storage facility in 1975 after 20 years of oil and gas production.In our simulations,the geomechanical behavior of the sand reservoir is modeled using two models:(1)a linear elastic model(non-hysteretic stress path)that does not take into consideration irreversible deformation,and(2)a plastic cap mechanical model which considers changes in rock elastic properties due to irreversible deformations caused by plastic reservoir compaction(hysteretic stress path).It shows that the irreversible compaction of the geological layer over geologic time and during the reservoir depletion can have important consequences on stress tensor orientation and magnitude.Ignoring depletion-induced irreversible compaction can lead to an over-estimation of the calculation of the maximum working reservoir pressure.Moreover,this irreversible compaction may bring the nearby faults closer to reactivation.However,regardless of the two models applied,the geomechanical analysis shows that for the estimated stress conditions applied in this study,the Honor Rancho Underground Storage Facility is being safely operated at pressures much below what would be required to compromise the seal integrity.展开更多
文摘The aerosolization and diffusion of radioactive materials caused by chemical explosions represent a typical nuclear accident scenario that poses severe radioactive hazards to human health and the environment.This study examines the diffusion of plutonium aerosol generated by a chemical explosion within a typical representative underground facility.The state of explosion products following a single-point detonation of explosives was simulated.Subsequently,a numerical simulation of plutonium aerosol diffusion using the discrete phase model(DPM)was conducted based on the outcomes of the chemical explosion simulation.The simulation results indicate that plutonium aerosols diffuse throughout underground facilities after a chemical explosion;small particle size aerosols primarily accumulate in the upper part of the room after the accident;the concentrations of plutonium aerosol in the room and tunnel are significantly higher than those in the other areas;and the temporal variations in aerosol concentration in each area were quantified.Based on the particle concentration distribution and the effective dose computation approach,the study computes the internal irradiation dose received by personnel in seven areas over various time periods post-accident.Recommendations for emergency decision-making were derived from these calculations.These findings provide important theoretical insight and practical engineering application value for understanding the diffusion of radioactive aerosol in confined spaces following chemical explosions and for evaluating personnel radiation dose.
文摘This study centers on the use of smart technology to improve the lifecycle management of underground facilities.It presents a comprehensive digital solution that addresses the challenges of underground facilities,particularly those related to the extensive use of underground space,as well as the requirements for safety,sustainability,and quality of services.The proposed solution emerged from discussions with experts,companies,and cities involved in the design,construction,and management of underground facilities.In this paper,we first discuss the major challenges of underground facilities,then,we present the development of a smart solution to address these challenges.This study demonstrates a promising perspective for the use of smart technology in the optimal management of underground facilities,and paves the way for its implementation.
基金supported by the National Natural Science Foundation of China(Grant Nos.52378083 and 52078481)the Natural Science Foundation of Jiangsu Province(Grant No.BK20231488).
文摘Subways,underground logistics systems and underground parking,as the primary facilities types of underground,contribute significantly to the achievement of carbon–neutral cities by moving surface transportation to underground,thereby releasing surface space for the creation of more urban blue-green space for carbon sink.Therefore,in-depth studies on carbon neutrality strategies as well as reliable layout optimization solutions of these three types of underground facilities are required.This study proposes a spatial layout optimization strategy for carbon neutrality using underground hydrogen storage and geothermal energy for these three types of underground facilities employing a multi-agent system model.First,three spatial layout relationships,competition,coordination,and followership,between five underground facilities that contribute to emission reduction were investigated.Second,the implementation steps for optimizing the spatial layout of underground facilities were determined by defining the behavioral guidelines for spatial environment,underground facility,and synergistic agent.Finally,using the Tianfu New District in Chengdu City,China,as a case study,layouts of underground facilities under three different underground space development scenarios were simulated to verify the model.The findings of this study address the gap in the research on underground spatial facilities and their layout optimization in response to emission reduction.This study provided a significant reference for the study of underground space and underground resources at the planning level to aid in achieving carbon–neutral cities.
基金conducted with funding provided by the California Energy Commission under the contract PIR-16-027 for Research on Risk Management Framework for Underground Natural Gas infrastructure in California。
文摘In this study,we numerically investigate the influence of hysteretic stress path behavior on the seal integrity during underground gas storage operations in a depleted reservoir.Our study area is the Honor Rancho Underground Storage Facility in Los Angeles County(California,USA),which was converted into an underground gas storage facility in 1975 after 20 years of oil and gas production.In our simulations,the geomechanical behavior of the sand reservoir is modeled using two models:(1)a linear elastic model(non-hysteretic stress path)that does not take into consideration irreversible deformation,and(2)a plastic cap mechanical model which considers changes in rock elastic properties due to irreversible deformations caused by plastic reservoir compaction(hysteretic stress path).It shows that the irreversible compaction of the geological layer over geologic time and during the reservoir depletion can have important consequences on stress tensor orientation and magnitude.Ignoring depletion-induced irreversible compaction can lead to an over-estimation of the calculation of the maximum working reservoir pressure.Moreover,this irreversible compaction may bring the nearby faults closer to reactivation.However,regardless of the two models applied,the geomechanical analysis shows that for the estimated stress conditions applied in this study,the Honor Rancho Underground Storage Facility is being safely operated at pressures much below what would be required to compromise the seal integrity.
