聚变-裂变能源混合堆可行性及在我国核能发展中作用的分析

简要论述了核能在我国能源发展战略中的地位及聚变-裂变混合堆在核能持续发展中的重要作用。对以不久将来即可实现的ITER聚变装置作驱动堆芯、天然铀水冷裂变系统作包层的混合堆做了细致的分析。这种混合堆型可以实现GWe级净电功率输出,年造钚1 656 kg,支持2.68个同功率压水堆电站对易裂变燃料的需要。初步的经济评估说明,混合堆电的成本是同功率压水堆电成本的1.67倍;而在不计燃料成本的情况下,混合堆与压水堆组合系统电的成本是同功率压水堆电成本的1.18倍。考虑到一般压水堆需消耗大量的天然铀,加上铀浓缩成本,混合堆与压水堆组合系统电的成本,与压水堆电的成本是可以相比拟的。     

为什么我不担心日本的核电站

下文是Josef Oehmen博士私人博客的文章,被MIT官方网站采用。据原载作者介绍,Josef Oehmen博士的父亲在德国核工业具有深厚的经验。原文地址有所更改,且文章中的一些内容经过了MIT一些专业人士的补充。尤其在核反应原理上,给出了比较详细的解释。     

可用汽油和生物燃料工作的通用发电机

美国阿贡国家实验室制造了一种新型汽车发电机,这种发电机可以使用随便一种可借火花点燃的燃料即可工作。与一般发电机不同的是,它可以使用由普通汽油、酒精或丁醇等混合燃料工作。     

梅赛德斯-奔驰使用科莱恩和Haltermann的第二代生物燃料

正近日,科莱恩、Haltermann以及梅赛德斯-奔驰强强联手,通过车队测试推出了一款未来燃料。科莱恩首先利用其sunliquid工艺将麦秸转化成纤维素乙醇。随后,Haltermann公司将纤维素乙醇与传统燃料混合,形成新型燃料。纤维素乙醇的生产过程几乎呈二氧化碳中性,因此与汽油相比,减少了几乎100%的二氧化碳排放量。sunliquid含有20%的纤维素乙醇,根据"能源开采到使用"(well-to-wheel)的比较研     

ID-临界因子图的度和条件

本文研究ID-因子临界图的度和条件,得到使得图G是ID-因子临界图的任意两个不相邻的顶点的度和的下界,同时说明这些结果是最好可能的。     

导出匹配可扩二部图度和条件的改进

研究并改进了导出匹配可扩二部图的度和条件.主要结论如下:若图G是一个有二部划分(A,B)的二部图,且|A|=|B|=n=3k+1(k≥2),如果对图G中任意不相邻的顶点u和v,有d(u)+d(v)≥4k+1,那么图G是导出匹配可扩的,并且该结果是最佳可能的.     

真空条件下可凝挥发物蒸发和凝结速率的分析

基于对具有极低饱和蒸汽压的润滑脂用基础油的挥发情况分析,研究了地面蒸发速率测试设备用敞开式油池代替小孔式油盒对单向蒸发速率有何影响,以及航天器空间真空度是否对可凝挥发物的蒸发与凝结产生影响,提出了不知道油脂的摩尔质量时预测其他温度下油面单向蒸发速率的方法.考虑到用敞开式油池代替小孔式油盒对沉积到盘上的蒸汽比例的影响,给出了与蒸发面平行且同轴的沉积表面的几何因子表达式,证明如果用敞开式油池代替小孔式油盒,蒸发速率急剧增加,而沉积到盘上的蒸汽比例减少得并不多.最后,探讨了本文观点的价值和限度,并加以总结.     

关注爱达荷核工程，评估奥巴马能源计划——该项目是核燃料和氢燃料能否作为美国未来的能源解决方案的风向标

一项用来评量当选总统巴拉克·奥巴马能源政策的先导项目将会为爱达荷州国家实验室的一个商业示范工程提供资金,援助他们利用高温氦冷却核动力来产生氢和热能(http://designnews.com.     

高海拔长日低温条件下选择水稻光温敏核不育系的效果和方法研究

在高海拔长日低温、低海拔日高温、低海拔长日高温和人工气候室长光低温条件下，进行了光温敏不育水稻分离世代的不育株出现频率以及选择实用型不育系的效果和选择方法的研究。     

新能源近期的发展态势

介绍了国内外新能源的研发现状，指出了新能源的发展前景。     

惯性约束聚变／裂变混合堆核能系统的概念研究

在惯性约束聚变尚未达到能量得失相当的条件下，以惯性约束聚变产生的中子作为驱动源，￣（２３８）Ｕ或￣（２３９）Ｐｕ与￣（２３８）Ｕ的混合物作为包层核燃料，进行了聚变裂变混合放能系统的概念研究。提出了以少量￣（２３９）Ｐｕ作为“助燃剂”，用以提高包层能量倍增的概念。￣（２３９）Ｐｕ的引入提高了包层的通量水平，加速了￣（２３８）Ｕ的造钚和钚的燃烧过程，实现了消耗￣（２３８）Ｕ释放能量而不消耗或很少消耗￣（２３９）Ｐｕ，并使包层能量倍增达到３０以上，从而为惯性约束聚变的早期应用和以￣（２３８）Ｕ为裂变能源燃料的持续发展提出了一条可能的途径。     

事故工况下乏燃料运输容器跌落分析

目的验证乏燃料运输容器本体、内外盖、吊篮和螺栓及其运输包装设计,在事故工况中以最危险角度从9 m高度自由跌落至水平的刚性地面过程中,是否满足GB 11806《放射性物质安全运输规定》的规范要求。方法采用LS-DYNA进行有限元仿真模拟跌落过程以代替跌落试验,开展乏燃料运输容器9 m自由跌落冲击分析,并根据ASME规范第III卷规定的应力限值对容器本体、内外盖、吊篮和螺栓进行应力校核。结果应力校核结果显示,乏燃料运输容器本体、内外盖、吊篮和螺栓满足设计强度要求。结论该乏燃料运输容器本体、内外盖、吊篮和螺栓及其运输包装设计满足GB 11806规范要求。     

加速器驱动次临界系统（ADS）与核能可持续发展

核废物最少化是核裂变能可持续发展的关键问题。加速器驱动次临界系统（ADS）是一种高效的核废物嬗变器（或焚烧炉）,是解决核废物的关键技术。文章主要介绍了ADS的基本原理及其对先进加速器、先进冷却性技术等方面的带动作用,并对各国ADS的研究现状进行了比较,最后提出了ADS发展必须解决的关键问题及其与国内核能发展的关系。     

多行政区域的能源资源开发利用的优化宏观经济模型

本文基于多行政区域国家的社会实践,引入国家内部每个行政区域效用乘积的联合效用函数,去衡量多区域国家在某一时间的效用密度,将国家的宏观层次目标与各个行政区域的地区目标联系起来.以联合效用函数在所考虑时间段上的积分最大化为目标,建立了能源资源开发利用的效率与公平统一的经济、能源、环境一体化模型,并给出了这一模型的数值解法.本文不仅对多行政区域国家的反污染政策及其经济–环境影响进行了理论分析,还提出了能源、反污染策略在多个行政区域间的最优配置执行方案,为我国实现能源资源可持续开发利用战略提供有效决策支持.     

Thermal Conductivity of Simulated Fuels with Dissolved Fission Products

The thermal diffusivity of simulated fuels with dissolved fission products was measured by using the laser-flash method in the temperature range from room temperature to 1,473 K. Three kinds of simulated fuels with an equivalent burn-up of 3, 6, and 12 at% were used in the measurement. The thermal diffusivity and the thermal conductivity of the simulated fuels with the dissolved fission products decreased, as the temperature and the equivalent burn-up increased. The thermal conductivities of simulated fuels with equivalent burn-ups of 3, 6, and 12 at% were lower than that of UO₂ by 84.70, 67.17, and 44.97% at 300 K and 99.17, 89.88, and 80.56% of UO₂ at 1,473 K, respectively. The difference in the thermal conductivity between the simulated fuel and UO₂ was large at room temperature, and it decreased as the temperature increased. The thermal resistivity of the simulated fuels increased linearly with temperature up to 1,473 K.     

Nuclear fuels and development of nuclear fuel elements

The importance of nuclear energy in meeting future energy demands has been well-recognised and a variety of nuclear reactor systems have been developed. Inherent characteristics of nuclear technology like neutron economy and neutron irradiation-induced degradation in properties of materials require stringent control of material purity and necessarily limit the choice of candidate materials. Hence safe, reliable and economic operation of nuclear fission reactors, the source of nuclear power at present, requires judicious choice, careful preparation and specialised fabrication procedures for fuels and fuel element structural materials. These aspects of nuclear fuels (uranium, plutonium and their oxides and carbides), fuel element technology and structural materials (aluminium, zircaloy, stainless steel etc.) are discussed with particular reference to research and power reactors in India, e.g. theDhruva research reactor atBarc, Trombay, the pressurised heavy water reactors (Phwr) at Rajasthan and Kalpakkam, and the Fast Breeder Test Reactor (Fbtr) at Kalpakkam. Other reactors like the gas-cooled reactors operating in UK are also mentioned. Because of the limited uranium resources, India has opted for a three-stage nuclear power programme aimed at the ultimate utilization of her abundant thorium resources. The first phase consists of natural uranium dioxide-fuelled, heavy water-moderated and cooledPhwr. The second phase was initiated with the attainment of criticality in theFbtr at Kalpakkam. Fast Breeder Reactors (Fbr) utilize the plutonium and uranium by-products of phase 1. Moreover,Fbr can convert thorium into fissile U-233. They produce more fuel than is consumed — hence, the name breeders. The fuel parameters of some of the operating or proposed fast reactors in the world are compared.Fbtr is unique in the choice of mixed carbides of plutonium and uranium as fuel. Factors affecting the fuel element performance and life in various reactors e.g. hydriding of zircaloys, fuel pellet-cladding interaction etc. inPhwr and void swelling, irradiation creep and helium embrittlement of fuel element structural materials inFbr are discussed along with measures to overcome some of these problems. Lecture presented at the Frontier Symposium of the Engineering Sciences Session of the 75th Indian Science Congress, Pune, January 9, 1988     

Thermal Conductivity of a Simulated Fuel with Dissolved Fission Products

The thermal diffusivity of a simulated fuel with fission products forming a solid solution was measured using the laser-flash method in the temperature range from room temperature to 1673 K. The density and the grain size of the simulated fuel with the solid solutions used in the measurement were 10.49 g · cm⁻³ (96.9% of theoretical density) at room temperature and 9.5 μm, respectively. The diameter and thickness of the specimens were 10 and 1 mm, respectively. The thermal diffusivity decreased from 2.108 m² · s⁻¹ at room temperature to 0.626 m² · s⁻¹ at 1673 K. The thermal conductivity was calculated by combining the thermal diffusivity with the specific heat and density. The thermal conductivity of the simulated fuel with the dissolved fission products decreased from 4.973 W · m⁻¹ · K⁻¹ at 300 K to 2.02 W · m⁻¹ · K⁻¹ at 1673 K. The thermal conductivity of the simulated fuel was lower than that of UO₂ by 34.36% at 300 K and by 15.05% at 1673 K. The difference in the thermal conductivity between the simulated fuel and UO₂ was large at room temperature, and decreased with an increase in temperature. Paper presented at the Seventeenth European Conference on Thermophysical Properties, September 5–8, 2005, Bratislava, Slovak Republic.     

Development Prospects for Acceptance Testing for Means of Metering and Recording Energy Resources

The current status is considered for testing and type approval for means of measurement on the basis of the legal and regulatory framework, the hardware, staff, data support, and analyses.     

Thermal Expansion of a Simulated Fuel with Fission Products Forming Solid Solutions

Thermal expansions of UO₂ and a simulated fuel with fission products forming a solid solution were studied using a dilatometer in the temperature range from 298 to 1800 K. The densities of the UO₂ and the simulated fuel used in the measurements were 10.43 g · cm⁻³ (95.2% of theoretical density (TD)) and 10.35 g · cm⁻³ (95.6% of TD), respectively. The linear thermal expansion of the simulated fuel is higher than that of UO₂, and the difference between this fuel and UO₂ increases monotonically with temperature. The average linear thermal expansion coefficients of UO₂ and the simulated fuel are 1.09× 10⁻⁵ and 1.23×10⁻⁵ K⁻¹, respectively. As the temperature increases to 1800 K, the relative densities of UO₂ and the simulated fuel decrease to 95.1 and 94.7% of their initial densities at 298 K.Paper presented at the Seventh Asian Thermophysical Properties Conference, August 23–28, 2004, Hefei and Huangshan, Anhui, P. R. China.