钍基熔盐堆(Thorium Molten Salt Reactor,TMSR)控制棒通道套管是典型的承受外压的高温薄壁长圆柱壳,蠕变-屈曲失稳是其主要失效模式。本文旨在利用数值模拟方法研究控制棒通道套管高温下的蠕变屈曲失稳行为。首先基于UNS N10003合金的...钍基熔盐堆(Thorium Molten Salt Reactor,TMSR)控制棒通道套管是典型的承受外压的高温薄壁长圆柱壳,蠕变-屈曲失稳是其主要失效模式。本文旨在利用数值模拟方法研究控制棒通道套管高温下的蠕变屈曲失稳行为。首先基于UNS N10003合金的高温蠕变试验数据获得了该材料的Norton蠕变模型及材料参数;然后利用有限元分析软件ABAQUS进行了TMSR控制棒通道套管的特征值屈曲分析与蠕变屈曲分析,并对屈曲失稳的关键因素进行了敏感性分析,获得了蠕变屈曲寿命的经验公式。分析结果表明,温度、压力、结构尺寸均会对套管的蠕变屈曲寿命产生显著影响。本文的研究结果对TMSR控制棒通道套管以及复杂结构与载荷条件下的高温结构的稳定性设计提供了工程指导依据,也为其他高温薄壁结构的蠕变屈曲寿命预测提供了依据。展开更多
钍基熔盐堆(TMSR)核能系统项目是中科院未来10年先导研究专项之一,其研究目标是研发第四代裂变反应堆核能系统,计划至2020年之前建成2MW钍基熔盐实验堆,形成支撑未来TMSR核能系统发展的若干技术研发能力,并解决钍铀燃料循环和钍基熔盐...钍基熔盐堆(TMSR)核能系统项目是中科院未来10年先导研究专项之一,其研究目标是研发第四代裂变反应堆核能系统,计划至2020年之前建成2MW钍基熔盐实验堆,形成支撑未来TMSR核能系统发展的若干技术研发能力,并解决钍铀燃料循环和钍基熔盐堆相关重大技术挑战,研制出工业示范级钍基熔盐堆,实现钍资源的有效使用和核能的综合利用。钍基核燃料具有232Th/233U转换效率高、在热中子堆中也能增殖、产生较少的高毒性放射性核素、有利于防核扩散等优点,但也面临燃料制备困难、232U衰变子核的强γ辐射给乏燃料处理和燃料再加工带来的困难、钍铀转换反应链中间核233Pa会吸收堆内中子从而影响233U产量。核燃料利用的工作模式有开环模式、改进的开环模式和闭环模式。熔盐堆是第四代反应堆的6个候选堆型之一,非常适合用作钍铀燃料循环,熔盐堆加上干法在线分离技术有可能实现完全的钍铀燃料闭式循环。本世纪初提出的氟盐冷却高温堆(Fluoride salt-cooled High temperature Reactors,FHRs),用氟化熔盐作为冷却剂,采用TRISO燃料颗粒作为核燃料,其中球床型氟盐冷却高温堆可以在改进的开环模式实现钍铀燃料循环。熔盐堆良好的高温特性使其成为核能非电应用主要候选者之一,反应堆产生的高温热可直接用于页岩油开采和高温制氢等工业领域。展开更多
基于最新发布的评价核数据库ENDF/B-VII.1,简要介绍了利用标准程序NJOY加工固态燃料钍基熔盐堆(Thorium Molten Salt Reactor-Solid Fuel,TMSR-SF)中子能谱测量所需温度下多群截面库的过程。详细分析了两个典型的核素加工所得核反应道...基于最新发布的评价核数据库ENDF/B-VII.1,简要介绍了利用标准程序NJOY加工固态燃料钍基熔盐堆(Thorium Molten Salt Reactor-Solid Fuel,TMSR-SF)中子能谱测量所需温度下多群截面库的过程。详细分析了两个典型的核素加工所得核反应道的多群截面与温度的关系,并将不同温度下的截面库用于中子能谱测量,分析了中子能谱测量结果的误差与温度所引起截面库变化的关系。结果表明,不同类型核反应道的截面所受温度影响不同,特别是核素对超热中子的截面存在共振峰问题受温度影响最大,这是由于多普勒效应影响,所以中子能谱测量结果受核反应道选择的影响符合物理规律,加工所得873 K下的核截面库可用于TMSR-SF相关中子能谱测量。展开更多
功率控制系统(Power Control System,PCS)是反应堆控制系统(Reactor Control System,RCS)的重要组成部分,它完成功率提升、功率保持与功率调节的作用。在钍基熔盐堆(Thorium Molten Salt Reactor,TMSR)核能系统固态堆设计方案中,功率控...功率控制系统(Power Control System,PCS)是反应堆控制系统(Reactor Control System,RCS)的重要组成部分,它完成功率提升、功率保持与功率调节的作用。在钍基熔盐堆(Thorium Molten Salt Reactor,TMSR)核能系统固态堆设计方案中,功率控制器根据实测功率与设定功率值之间的偏差和偏差的变化趋势,按照经典的比例-积分-微分(Proportional Integral Derivative,PID)控制算法,给出调节控制棒的运动距离和运动方向等信号。PCS的PID算法设计与基于反应堆中子物理、热工及控制棒的传动性能构成的闭环控制系统的特性有关,其不同参数的确定与系统的静态和动态性能指标的要求相对应。本文从控制的角度出发,在已有的控制棒样机中设计的棒控棒位系统及相关中子物理的基础上对PCS的PID算法进行多层次仿真与参数分析,并对系统的可控性与可测性进行分析验证。分析及仿真结果表明两种控制模型下的系统均是完全可控及完全可测的,在合适的PID参数集下均能体现响应的快速性及系统的良好鲁棒性和抗干扰能力,具有实际的应用意义。展开更多
中子动态参数的准确分析与反应堆的安全特性紧密相关。固态燃料钍基熔盐实验堆(Thorium-based Molten Salt experiment Reactor with Solid Fuel,TMSR-SF1)作为第四代新堆型,采用蒙特卡罗输运程序计算其动态参数更有利于核安全评审。本...中子动态参数的准确分析与反应堆的安全特性紧密相关。固态燃料钍基熔盐实验堆(Thorium-based Molten Salt experiment Reactor with Solid Fuel,TMSR-SF1)作为第四代新堆型,采用蒙特卡罗输运程序计算其动态参数更有利于核安全评审。本文基于较通用的蒙特卡罗多粒子输运(Monte Carlo N Particle Transport Code,MCNP)程序,植入了动态参数直接统计方法,用于计算TMSR-SF1中的有效缓发中子份额和有效中子代时间。通过多个ICSBEP(International Criticality Safety Benchmark Evaluation Project)基准题的检验,计算结果与基准题实验误差在±5%以内,证明了该方法的准确性。运用该方法计算得到TMSR-SF1中6组有效缓发中子份额和有效中子代时间随燃耗深度的变化,其计算结果与采用MCNP共轭通量方法所得的数据误差在±3%以内,证明该方法用于TMSR-SF1的动态参数分析是合理可靠的。展开更多
The solid-fueled thorium molten salt reactor(TMSR-SF1) is a 10 MW_(th) test reactor design to be deployed in 5-10 years by the TMSR group.Its design combines coated particle fuel and molten FLiBe coolant for great int...The solid-fueled thorium molten salt reactor(TMSR-SF1) is a 10 MW_(th) test reactor design to be deployed in 5-10 years by the TMSR group.Its design combines coated particle fuel and molten FLiBe coolant for great intrinsic safety features and economic advantages.Due to a large amount of beryllium in the coolant salt,photoneutrons are produced by(y,n) reaction,hence the increasing fraction of effective delayed neutrons in the core by the photoneutrons originating from the long-lived fission products.Some of the delayed photoneutron groups are of long lifetime,so a direct effect is resulted in the transient process and reactivity measurement.To study the impact of photoneutrons for TMSR-SF1,the effective photoneutron fraction is estimated using k-ratio method and performed by the Monte Carlo code(MCNP5) with ENDF/B-Ⅶ cross sections.Based on the coupled neutronphoton point kinetics equations,influence of the photoneutrons is analyzed.The results show that the impact of photoneutrons is not negligible in reactivity measurement.Without considering photoneutrons in on-line reactivity measurement based on inverse point kinetics can result in overestimation of the positive reactivity and underestimation of the negative reactivity.The photoneutrons also lead to more waiting time for the doubling time measurement.Since the photoneutron precursors take extremely long time to achieve equilibrium,a "steady" power operation may not directly imply a "real" criticality.展开更多
The solid fuel thorium molten salt reactor(TMSR-SF1) is a 10-MWth fluoride-cooled pebble bed reactor. As a new reactor concept, one of the major limiting factors to reactor lifetime is radiation-induced material damag...The solid fuel thorium molten salt reactor(TMSR-SF1) is a 10-MWth fluoride-cooled pebble bed reactor. As a new reactor concept, one of the major limiting factors to reactor lifetime is radiation-induced material damage. The fast neutron flux(E > 0.1 MeV) can be used to assess possible radiation damage. Hence, a method for calculating high-resolution fast neutron flux distribution of the full-scale TMSR-SF1 reactor is required. In this study,a two-step subsection approach based on MCNP5 involving a global variance reduction method, referred to as forward-weighted consistent adjoint-driven importance sampling, was implemented to provide fast neutron flux distribution throughout the TMSR-SF1 facility. In addition,instead of using the general source specification cards, the user-provided SOURCE subroutine in MCNP5 source code was employed to implement a source biasing technique specialized for TMSR-SF1. In contrast to the one-step analog approach, the two-step subsection approach eliminates zero-scored mesh tally cells and obtains tally results with extremely uniform and low relative uncertainties.Furthermore, the maximum fast neutron fluxes of the main components in TMSR-SF1 are provided, which can be used for radiation damage assessment of the structural materials.展开更多
In order to comply with discharge standards, a gas–solid separator is used to remove solid particles from the thorium molten salt reactor-solid fuel (TMSR-SF) system. As a key component, it directly determines system...In order to comply with discharge standards, a gas–solid separator is used to remove solid particles from the thorium molten salt reactor-solid fuel (TMSR-SF) system. As a key component, it directly determines system energy efficiency. However, current gas–solid separators, based on activated carbon adsorption technology, result in high pressure drops and increased maintenance costs. In the present study, a new combined gas–solid separator was developed for the TMSR-SF. Based on a simplified computational fluid dynamics (CFD) model, the gas–solid twophase flow and the motion trajectory of solid particles were simulated for this new separator using commercial ANSYS 16.0 software. The flow and separation mechanism for this structure were also been discussed in terms of their velocity effects and pressure field distributions, and then the structure was optimized based on the influence of key structural parameters on pressure and separation efficiency. The results showed that the standard k–ε model could be achieved and accurately simulated the new combined separator. In this new combined gas–solid separator, coarse particles are separated in the first stage using rotating centrifugal motion, and then fine particles are filtered in the second stage, giving a separation efficiency of up to 96.11%. The optimum blade inclination angle and numbers were calculated to be 45° and four, respectively. It implicated that the combined separator could be of great significance in a wide variety of applications.展开更多
文摘钍基熔盐堆(Thorium Molten Salt Reactor,TMSR)控制棒通道套管是典型的承受外压的高温薄壁长圆柱壳,蠕变-屈曲失稳是其主要失效模式。本文旨在利用数值模拟方法研究控制棒通道套管高温下的蠕变屈曲失稳行为。首先基于UNS N10003合金的高温蠕变试验数据获得了该材料的Norton蠕变模型及材料参数;然后利用有限元分析软件ABAQUS进行了TMSR控制棒通道套管的特征值屈曲分析与蠕变屈曲分析,并对屈曲失稳的关键因素进行了敏感性分析,获得了蠕变屈曲寿命的经验公式。分析结果表明,温度、压力、结构尺寸均会对套管的蠕变屈曲寿命产生显著影响。本文的研究结果对TMSR控制棒通道套管以及复杂结构与载荷条件下的高温结构的稳定性设计提供了工程指导依据,也为其他高温薄壁结构的蠕变屈曲寿命预测提供了依据。
文摘钍基熔盐堆(TMSR)核能系统项目是中科院未来10年先导研究专项之一,其研究目标是研发第四代裂变反应堆核能系统,计划至2020年之前建成2MW钍基熔盐实验堆,形成支撑未来TMSR核能系统发展的若干技术研发能力,并解决钍铀燃料循环和钍基熔盐堆相关重大技术挑战,研制出工业示范级钍基熔盐堆,实现钍资源的有效使用和核能的综合利用。钍基核燃料具有232Th/233U转换效率高、在热中子堆中也能增殖、产生较少的高毒性放射性核素、有利于防核扩散等优点,但也面临燃料制备困难、232U衰变子核的强γ辐射给乏燃料处理和燃料再加工带来的困难、钍铀转换反应链中间核233Pa会吸收堆内中子从而影响233U产量。核燃料利用的工作模式有开环模式、改进的开环模式和闭环模式。熔盐堆是第四代反应堆的6个候选堆型之一,非常适合用作钍铀燃料循环,熔盐堆加上干法在线分离技术有可能实现完全的钍铀燃料闭式循环。本世纪初提出的氟盐冷却高温堆(Fluoride salt-cooled High temperature Reactors,FHRs),用氟化熔盐作为冷却剂,采用TRISO燃料颗粒作为核燃料,其中球床型氟盐冷却高温堆可以在改进的开环模式实现钍铀燃料循环。熔盐堆良好的高温特性使其成为核能非电应用主要候选者之一,反应堆产生的高温热可直接用于页岩油开采和高温制氢等工业领域。
文摘功率控制系统(Power Control System,PCS)是反应堆控制系统(Reactor Control System,RCS)的重要组成部分,它完成功率提升、功率保持与功率调节的作用。在钍基熔盐堆(Thorium Molten Salt Reactor,TMSR)核能系统固态堆设计方案中,功率控制器根据实测功率与设定功率值之间的偏差和偏差的变化趋势,按照经典的比例-积分-微分(Proportional Integral Derivative,PID)控制算法,给出调节控制棒的运动距离和运动方向等信号。PCS的PID算法设计与基于反应堆中子物理、热工及控制棒的传动性能构成的闭环控制系统的特性有关,其不同参数的确定与系统的静态和动态性能指标的要求相对应。本文从控制的角度出发,在已有的控制棒样机中设计的棒控棒位系统及相关中子物理的基础上对PCS的PID算法进行多层次仿真与参数分析,并对系统的可控性与可测性进行分析验证。分析及仿真结果表明两种控制模型下的系统均是完全可控及完全可测的,在合适的PID参数集下均能体现响应的快速性及系统的良好鲁棒性和抗干扰能力,具有实际的应用意义。
文摘中子动态参数的准确分析与反应堆的安全特性紧密相关。固态燃料钍基熔盐实验堆(Thorium-based Molten Salt experiment Reactor with Solid Fuel,TMSR-SF1)作为第四代新堆型,采用蒙特卡罗输运程序计算其动态参数更有利于核安全评审。本文基于较通用的蒙特卡罗多粒子输运(Monte Carlo N Particle Transport Code,MCNP)程序,植入了动态参数直接统计方法,用于计算TMSR-SF1中的有效缓发中子份额和有效中子代时间。通过多个ICSBEP(International Criticality Safety Benchmark Evaluation Project)基准题的检验,计算结果与基准题实验误差在±5%以内,证明了该方法的准确性。运用该方法计算得到TMSR-SF1中6组有效缓发中子份额和有效中子代时间随燃耗深度的变化,其计算结果与采用MCNP共轭通量方法所得的数据误差在±3%以内,证明该方法用于TMSR-SF1的动态参数分析是合理可靠的。
基金supported by the "Strategic Priority Research Program" of the Chinese Academy of Sciences(No.XDA02010000)the Frontier Science Key Program of the Chinese Academy of Sciences(No.QYZDY-SSW-JSC016)
文摘The solid-fueled thorium molten salt reactor(TMSR-SF1) is a 10 MW_(th) test reactor design to be deployed in 5-10 years by the TMSR group.Its design combines coated particle fuel and molten FLiBe coolant for great intrinsic safety features and economic advantages.Due to a large amount of beryllium in the coolant salt,photoneutrons are produced by(y,n) reaction,hence the increasing fraction of effective delayed neutrons in the core by the photoneutrons originating from the long-lived fission products.Some of the delayed photoneutron groups are of long lifetime,so a direct effect is resulted in the transient process and reactivity measurement.To study the impact of photoneutrons for TMSR-SF1,the effective photoneutron fraction is estimated using k-ratio method and performed by the Monte Carlo code(MCNP5) with ENDF/B-Ⅶ cross sections.Based on the coupled neutronphoton point kinetics equations,influence of the photoneutrons is analyzed.The results show that the impact of photoneutrons is not negligible in reactivity measurement.Without considering photoneutrons in on-line reactivity measurement based on inverse point kinetics can result in overestimation of the positive reactivity and underestimation of the negative reactivity.The photoneutrons also lead to more waiting time for the doubling time measurement.Since the photoneutron precursors take extremely long time to achieve equilibrium,a "steady" power operation may not directly imply a "real" criticality.
基金supported by the Chinese TMSR Strategic Pioneer Science and Technology Project(No.XDA02010000)the Frontier Science Key Program of Chinese Academy of Sciences(No.QYZDY-SSW-JSC016)
文摘The solid fuel thorium molten salt reactor(TMSR-SF1) is a 10-MWth fluoride-cooled pebble bed reactor. As a new reactor concept, one of the major limiting factors to reactor lifetime is radiation-induced material damage. The fast neutron flux(E > 0.1 MeV) can be used to assess possible radiation damage. Hence, a method for calculating high-resolution fast neutron flux distribution of the full-scale TMSR-SF1 reactor is required. In this study,a two-step subsection approach based on MCNP5 involving a global variance reduction method, referred to as forward-weighted consistent adjoint-driven importance sampling, was implemented to provide fast neutron flux distribution throughout the TMSR-SF1 facility. In addition,instead of using the general source specification cards, the user-provided SOURCE subroutine in MCNP5 source code was employed to implement a source biasing technique specialized for TMSR-SF1. In contrast to the one-step analog approach, the two-step subsection approach eliminates zero-scored mesh tally cells and obtains tally results with extremely uniform and low relative uncertainties.Furthermore, the maximum fast neutron fluxes of the main components in TMSR-SF1 are provided, which can be used for radiation damage assessment of the structural materials.
文摘In order to comply with discharge standards, a gas–solid separator is used to remove solid particles from the thorium molten salt reactor-solid fuel (TMSR-SF) system. As a key component, it directly determines system energy efficiency. However, current gas–solid separators, based on activated carbon adsorption technology, result in high pressure drops and increased maintenance costs. In the present study, a new combined gas–solid separator was developed for the TMSR-SF. Based on a simplified computational fluid dynamics (CFD) model, the gas–solid twophase flow and the motion trajectory of solid particles were simulated for this new separator using commercial ANSYS 16.0 software. The flow and separation mechanism for this structure were also been discussed in terms of their velocity effects and pressure field distributions, and then the structure was optimized based on the influence of key structural parameters on pressure and separation efficiency. The results showed that the standard k–ε model could be achieved and accurately simulated the new combined separator. In this new combined gas–solid separator, coarse particles are separated in the first stage using rotating centrifugal motion, and then fine particles are filtered in the second stage, giving a separation efficiency of up to 96.11%. The optimum blade inclination angle and numbers were calculated to be 45° and four, respectively. It implicated that the combined separator could be of great significance in a wide variety of applications.
