氯盐快堆具有重金属溶解度高和能谱较硬等特性,是嬗变超铀核素(Transuranic elements,TRU)的理想堆型。本文提出了一种50 MW小型模块化氯盐快堆(small-Modular Chlorine salt Fast Reactor,sm-MCFR)方案,对其焚烧TRU特性进行了初步研究...氯盐快堆具有重金属溶解度高和能谱较硬等特性,是嬗变超铀核素(Transuranic elements,TRU)的理想堆型。本文提出了一种50 MW小型模块化氯盐快堆(small-Modular Chlorine salt Fast Reactor,sm-MCFR)方案,对其焚烧TRU特性进行了初步研究。采用了基于SCALE(Standardized Computer Analyses for Licensing Evaluation)和MODEC(MOlten Salt Reactor Specific DEpletion Code)开发的耦合程序TMCBurnup(TRITON MODEC Coupled Burnup Code),计算并分析了sm-MCFR在TRU+232Th和TRU+DU(Depleted Uranium)两种燃料方案下的临界、燃耗、核素演化和嬗变TRU等物理性能。结果表明:在sm-MCFR运行期间,为维持临界状态,需在线添加TRU,以确保有效增殖系数k_(eff)>1;满功率运行40 a时,采用TRU+Th燃料方案下堆芯剩余TRU量为657 kg,而采用TRU+DU燃料方案下剩余TRU量为725 kg,皆大于寿期初;采用TRU+Th和TRU+DU作为燃料盐时,嬗变率分别可达49%和41%,为实现乏燃料最小化提供了可行方案。展开更多
TRU(Teaching for Robust Understanding in Mathematics)课堂评价模型,是由加州大学伯克利分校与密西根大学共同开发研制的一项数学课堂评价工具,该模型从数学内容、认知需求、学习机会、学生表现度和课堂练习反馈五个维度分析课堂。...TRU(Teaching for Robust Understanding in Mathematics)课堂评价模型,是由加州大学伯克利分校与密西根大学共同开发研制的一项数学课堂评价工具,该模型从数学内容、认知需求、学习机会、学生表现度和课堂练习反馈五个维度分析课堂。本文介绍TRU评价模型的基本框架和特点,探讨该模型带给我国数学教育的启示:重视概念性和过程性学习、学情分析、重视学生自我观点阐述和对他人观点评价。展开更多
A molten salt reactor(MSR)has outstanding features considering the application of thorium fuel,inherent safety,sustainability,and resistance to proliferation.However,fissile material^(233)U is significantly rare at th...A molten salt reactor(MSR)has outstanding features considering the application of thorium fuel,inherent safety,sustainability,and resistance to proliferation.However,fissile material^(233)U is significantly rare at the current stage,thus it is difficult for MSR to achieve a pure thorium-uranium fuel cycle.Therefore,using plutonium or enriched uranium as the initial fuel for MSR is more practical.In this study,we aim to verify the feasibility of a small modular MSR that utilizes plutonium as the starting fuel(SM-MSR-Pu),and highlight its advantages and disadvantages.First,the structural design and fuel management scheme of the SM-MSR-Pu were presented.Second,the neutronic characteristics,such as the graphite-irradiation lifetime,burn-up performance,and coefficient of temperature reactivity were calculated to analyze the physical characteristics of the SM-MSR-Pu.The results indicate that plutonium is a feasible and advantageous starting fuel for a SM-MSR;however,there are certain shortcomings that need to be solved.In a 250 MWth SM-MSR-Pu,approximately 288.64 kg^(233)U of plutonium with a purity of greater than 90% is produced while 978.00 kg is burned every ten years.The temperature reactivity coefficient decreases from -4.0 to -6.5 pcm K^(-1) over the 50-year operating time,which ensures a long-term safe operation.However,the amount of plutonium and accumulation of minor actinides(MAs)would increase as the burn-up time increases,and the annual production and purity of^(233)U will decrease.To achieve an optimal burn-up performance,setting the entire operation time to 30 years is advisable.Regardless,more than 3600 kg of plutonium eventually accumulate in the core.Further research is required to effectively utilize this accumulated plutonium.展开更多
文摘氯盐快堆具有重金属溶解度高和能谱较硬等特性,是嬗变超铀核素(Transuranic elements,TRU)的理想堆型。本文提出了一种50 MW小型模块化氯盐快堆(small-Modular Chlorine salt Fast Reactor,sm-MCFR)方案,对其焚烧TRU特性进行了初步研究。采用了基于SCALE(Standardized Computer Analyses for Licensing Evaluation)和MODEC(MOlten Salt Reactor Specific DEpletion Code)开发的耦合程序TMCBurnup(TRITON MODEC Coupled Burnup Code),计算并分析了sm-MCFR在TRU+232Th和TRU+DU(Depleted Uranium)两种燃料方案下的临界、燃耗、核素演化和嬗变TRU等物理性能。结果表明:在sm-MCFR运行期间,为维持临界状态,需在线添加TRU,以确保有效增殖系数k_(eff)>1;满功率运行40 a时,采用TRU+Th燃料方案下堆芯剩余TRU量为657 kg,而采用TRU+DU燃料方案下剩余TRU量为725 kg,皆大于寿期初;采用TRU+Th和TRU+DU作为燃料盐时,嬗变率分别可达49%和41%,为实现乏燃料最小化提供了可行方案。
文摘TRU(Teaching for Robust Understanding in Mathematics)课堂评价模型,是由加州大学伯克利分校与密西根大学共同开发研制的一项数学课堂评价工具,该模型从数学内容、认知需求、学习机会、学生表现度和课堂练习反馈五个维度分析课堂。本文介绍TRU评价模型的基本框架和特点,探讨该模型带给我国数学教育的启示:重视概念性和过程性学习、学情分析、重视学生自我观点阐述和对他人观点评价。
基金supported by the Chinese TMSR Strategic Pioneer Science and Technology Project(No.XDA02010000)Chinese Academy of Sciences Talent Introduction Youth Program(No.SINAP-YCJH-202303)Chinese Academy of Sciences Special Research Assistant Funding Project and Shanghai Pilot Program for Basic Research-Chinese Academy of Science,Shanghai Branch(JCYJ-SHFY-2021-003)。
文摘A molten salt reactor(MSR)has outstanding features considering the application of thorium fuel,inherent safety,sustainability,and resistance to proliferation.However,fissile material^(233)U is significantly rare at the current stage,thus it is difficult for MSR to achieve a pure thorium-uranium fuel cycle.Therefore,using plutonium or enriched uranium as the initial fuel for MSR is more practical.In this study,we aim to verify the feasibility of a small modular MSR that utilizes plutonium as the starting fuel(SM-MSR-Pu),and highlight its advantages and disadvantages.First,the structural design and fuel management scheme of the SM-MSR-Pu were presented.Second,the neutronic characteristics,such as the graphite-irradiation lifetime,burn-up performance,and coefficient of temperature reactivity were calculated to analyze the physical characteristics of the SM-MSR-Pu.The results indicate that plutonium is a feasible and advantageous starting fuel for a SM-MSR;however,there are certain shortcomings that need to be solved.In a 250 MWth SM-MSR-Pu,approximately 288.64 kg^(233)U of plutonium with a purity of greater than 90% is produced while 978.00 kg is burned every ten years.The temperature reactivity coefficient decreases from -4.0 to -6.5 pcm K^(-1) over the 50-year operating time,which ensures a long-term safe operation.However,the amount of plutonium and accumulation of minor actinides(MAs)would increase as the burn-up time increases,and the annual production and purity of^(233)U will decrease.To achieve an optimal burn-up performance,setting the entire operation time to 30 years is advisable.Regardless,more than 3600 kg of plutonium eventually accumulate in the core.Further research is required to effectively utilize this accumulated plutonium.
