共查询到17条相似文献,搜索用时 62 毫秒
1.
2.
核燃料贮存、运输以及后处理过程中的安全是构成核与辐射安全的重要内容,为保证安全性,提高运输经济性,减小后处理厂对环境的排放,须获得乏燃料组件的包络源项,因此,采用ORIGEN-ARP程序分析组件运行历史、初始富集度、燃耗深度等参数对源项的影响。运行历史在卸料初期对源项略有影响,可采用合适的保守因子予以包络,在冷却一定时间后,其影响可忽略不计;初始富集度、燃耗深度均不同的组件须经对比计算以获得包络源项。计算表明:在目前核电厂乏燃料组件中,235U初始富集度为4.45%、燃耗深度为55 GW•d/tU的AFA-3G型组件源项是包络的,可作为乏燃料水池、运输容器设计,以及后处理厂排放源项分析的初始源项。 相似文献
3.
为了对示范快堆乏燃料组件的热工水力特性进行分析,自主研发了钠冷快堆乏燃料组件热工水力分析程序SPATANS。该程序基于子通道分析方法,采用适用于低流量下的流动换热和交混关系式。针对乏燃料组件棒束区进行计算,得到组件不同高度处各子通道的温度、压力等热工参数,并将计算结果与三维计算流体力学FLUENT程序的结果进行对比分析。结果表明:自主研发程序的计算结果与FLUENT程序的计算结果较为吻合,偏差在工程可接受范围内,且其计算效率明显高于FLUENT程序。初步表明SPATANS程序可用于钠冷快堆乏燃料组件热工水力分析,并具有良好的应用前景。 相似文献
4.
5.
6.
钠冷快堆乏燃料组件在转运过程中会暴露在气体环境中,散热性能明显下降。为预测乏燃料组件在气体环境中的温度分布,特别是避免燃料组件包壳最高温度超过设计限值,本文建立了基于多表面封闭系统网络法的数值模型,以此为基础开发了数值分析程序。通过与37棒束模拟组件实验数据的对比,验证了程序的可靠性。通过与Manteufel-Todreas双层模型预测结果的比较,证明了程序更具有保守性。另外,比较了均匀与非均匀加热两种情况下的温度分布,分析了加热功率、表面发射率对温度的影响。 相似文献
7.
概要综述了用无源和有源非破坏性分析技术测量动力堆乏燃料组件燃耗的基本原理、方法和实验装置。由电离室和裂变室组成的标准叉型探测器具有性能稳定可靠、分析速度快、操作简单、携带方便等优点。当前,它对LWR组件的燃耗测量值和申报值的偏差在±1%以内。用高分辨γ谱方法(HRGS)测量组件的燃耗,也能达到同样的精度。根据测量得到的中子计数或γ放射性,可以确定组件中可裂变物质的含量。 相似文献
8.
9.
10.
乏燃料组件在运输或转运过程中,组件会裸露在传热较差的气体介质内,需关注其散热性能。为模拟乏燃料组件的传热特性,采用多孔介质模型模拟组件的流动阻力,并利用等效热导率模型模拟组件内部的传热。由于自然对流条件下乏燃料组件内部流动符合层流假设,在多孔介质阻力模型中忽略了惯性力项的作用。将等效热导率模型的模拟结果与SNL-LMFBR实验结果进行对比,证明了该模拟方法的有效性。计算结果表明,在水平放置工况下乏燃料组件温度轴向呈对称分布,在竖直放置工况下轴向呈非对称分布,乏燃料组件的高温区域向组件上方偏移。 相似文献
11.
12.
《Journal of Nuclear Science and Technology》2013,50(9):925-930
This study used the Computational Fluid Dynamics (CFD) program CFX5 to investigate the flow field in planar fuel assemblies with two types of lifting beams, and to determine the effect of the two types of lifting beams on the flow field in planar fuel assemblies. This information is helpful in optimizing the design of a planar fuel assembly. The results indicated that the first type of lifting beam had a similar effect on the planar fuel assembly as the other type, the flow distribution in narrow flow channels between fuel plates with the first lifting beam was similar to the other, and the pressure difference of the inlet and outlet of the planar fuel assembly was also similar for the two types of lifting beams. The results also indicated that the two types of lifting beams' effect on the flow field in narrow flow channels between fuel plates is small, so either of the lifting beams could be used in the planar fuel assembly's design. 相似文献
13.
14.
Mechanical shearing systems are commonly used in reprocessing plants to crack spent fuel. The radioactive dust generated by shearing needs to be contained to ensure the full utilization of spent fuel pellets and the maintainability of the hot chamber. The airflow pattern and particle distribution and movement in the machine are of great significance to ensure the normal operation of the shearing machine. In order to supplement the deficiencies of experimental research and theoretical research, and improve dust distribution, reduce dust levels and optimize design of the shearing machine, the flow field in bar shearing machine with injected virtual particles was simulated based on the discrete particle model. By analyzing the distribution of velocity, pressure and turbulent kinetic energy of the fluid in shearing machine and the destructive effect of dust particles on the inner wall of shearing machine, the structure and boundary conditions of the shear were optimized. The results show that the eddy current, turbulence and high impact force can be effectively avoided by improving the structure of the flow passage and the input conditions. The velocity field, pressure field and turbulent kinetic energy distribution of gas-solid two-phase flow in the box are more uniform and the gradient change is smaller, and the damage of box wall is effectively reduced. 相似文献
15.
基于小型压水堆特有的截短型燃料组件,建立乏燃料贮存水池几何模型,分析正常贮存及事故工况下的临界安全。选取合理的保守假设,建立适当的计算模型,分别计算了一区和二区正常贮存工况、地震事故工况、组件跌落事故工况、新组件误插入事故工况的反应性。计算得到事故工况下有效增值因子最大值为0.932 83。小型压水堆乏燃料贮存水池临界安全分析中,正常工况及事故工况下计算结果均小于0.95。该设计模型可确保燃料堆内贮存区域处于次临界状态,且安全可控。 相似文献
16.
17.
Adem Acır 《Journal of Fusion Energy》2009,28(3):258-267
In this study, a numerical analysis and an analysis of variance (ANOVA) are applied to find the best suitable neutronic parameters
for the performance analysis in a thorium fusion rector. The numerical and ANOVA approach are employed to investigate the
neutronic characteristics of a fusion reactor using ThO2 90% + FR spent fuel 10% fuel mixtures. Three different neutronic parameters for the ANOVA and numerical approach, namely,
moderator/fuel volume fractions (Vm/Vf), plasma chamber dimensions (PCD) and neutron wall loading (NWLs) as time dependent are selected for neutronic performance
characteristics including tritium breeding ratio (TBR), multiplication factor (M), total fission rate (Σf), 232Th(n,γ) reaction, burn up and/or transmutation (B/T) and fissile fuel breeding (FFBR). Moreover, effects of the NWLs, Vm/Vf fractions and PCD in the B/T of FR spent fuel mixed thorium are investigated. Numerical and statistics approach results are
evaluated for TBR, M, Σf fission rate, 232Th(n,γ) reaction, B/T and FFBR. 相似文献