共查询到18条相似文献,搜索用时 46 毫秒
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5MW低功率堆辐照孔道内快中子通量谱测定 总被引:1,自引:0,他引:1
本文简要说明了测量快中子通量谱的阈探测片组激活方法,介绍了辐照孔道内快中子通量轴向相对分布的测量结果,报道了堆内 K_(11)、Ⅴ 和 Ⅶ 号辐照孔道内快中子通量谱和 Ⅴ 号孔道快中子积分通量的实验结果。并对实验结果进行了分析和讨论,为该堆的同位素生产和材料辐照提供了十分重要的数据。 相似文献
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为验证计算流体动力学(CFD)方法在钠冷快堆失流事故模拟计算中的可靠性和可行性,针对快中子通量实验堆(FFTF),建立了包含冷池、热池、堆芯在内的全三维模型,其中堆芯组件简化为多孔介质模型,堆芯保留了盒间特征,各类隔板简化为无厚度面。失流事故下主要参数计算结果与实验数据的对比表明,CFD方法能有效捕捉冷池、热池以及盒间复杂的流动换热现象,堆芯最热组件的位置在瞬态过程发生了变化,热管段出口温度与实验值符合良好,装有温度测点的组件出口温度模拟值较实验值低。CFD方法仍需针对组件盒间进行相应的模型开发和验证,此外还需进行大量全堆级别的实验验证,以保证计算结果的合理性。 相似文献
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微型堆辐照座内快中子通量谱的测定 总被引:2,自引:0,他引:2
用Al,Fe,In和Ni作探测片,用阈探测片活化法测定了中国原子能科学研究院微型堆内,外辐照孔道的快中子能量。用平均截面法求得内外辐照孔道的快中子与热中子能量比分别为0.198和0.077,用有效阈能法计算了不同能量区间的快中子通量,同时也对四个内辐照等之间及内、外辐照管内径向和轴向快中子通量的不均匀度进行了测定。 相似文献
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简要介绍了中国快中子脉冲堆-Ⅱ堆周期计算机测量系统的硬件结构,工作原理和软件组成,给出了CFBR-Ⅱ堆裸堆带去耦部件系统和裸堆上布置有较多轻材料样品的系统的裂变产额-预加反应性关系。该测量系统使CFBR-Ⅱ堆周期测量实现了自动化和智能化,提高了测量数据在线处理的精度和速度。 相似文献
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快中子脉冲堆动力学特性研究 总被引:2,自引:0,他引:2
快中子脉冲堆是一种可超瞬发运行的链式反应堆,在研究裂变反应堆瞬态物理过程和中子动力学过程等方面有重要的应用价值。介绍了快中子脉冲堆的动力学过程与特性,推导了动力学方程和超瞬发临界状态下的解析解。介绍了实验研究结果,测量了快中子脉冲堆超瞬发临界运行产生的脉冲中子辐射场的脉冲特性参数,获得了快中子脉冲堆中子动力学的基本特性参数。实验结果与建立的理论模型很好地符合。 相似文献
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利用MCNP程序建立了CFBR-Ⅱ堆结构的三维模型,借助中子倍增的方法实现了计算中子价值的功能。为消除实验中用中间钢托盘孔道内的中子价值代替上下半球的中子价值而引起的差异,利用均匀抽样技巧对各区域沿径向分层细致计算。结果表明,中子价值最大处位于高富集度铀区域中间某层而非系统中心或上下半球球心,其他区域中子价值则沿径向单调递减。 相似文献
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利用MCNP程序建立了CFBR-Ⅱ堆结构的三维模型,借助中子倍增的方法实现了计算中子价值的功能.为消除实验中用中间钢托盘孔道内的中子价值代替上下半球的中子价值而引起的差异,利用均匀抽样技巧对各区域沿径向分层细致计算.结果表明,中子价值最大处位于高富集度铀区域中间某层而非系统中心或上下半球球心,其他区域中子价值则沿径向单调递减. 相似文献
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《Journal of Nuclear Science and Technology》2013,50(5):267-276
The algorithm is presented for seeking optimal control of the steady state neutron flux distribution making use of Pontryagin's Maximum Principle, for a one group model of the bare slab reactor as well as for a two group model of the reflected slab reactor, both of which are homogeneous except for the control material. The performance criterion to be minimized is the spatial square integral error between the thermal flux distribution and the desired flux shape, and the control variable is the cross section of the absorbing material. A numerical example is given for the bare reactor where the desired shape is assumed to be uniformly flat. The non-linear nature of the problem imparts a complex aspect to the algorithm concerning the steepest descent method, as indicated by the numerical example. The results show that, as the bounds of the control variable are relaxed, the number of switchings is increased and a better performance criterion is obtained but this is accompanied by a higher hot spot factor. 相似文献
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Procedures are described for identifying and determining concentrations of trace impurities in minerals by means of neutron activation analysis with low neutron flux and standard gamma measurement equipment. Techniques developed in this work may be of use to those involved with the ever increasing need for mineral assays and for pollutant measurements, but who do not have the latest and most sophisticated equipment. This is especially true for institutions without formal nuclear programs and for developing countries desiring to be self-sustaining. 相似文献
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反应堆中子通量密度仿真研究 总被引:1,自引:1,他引:0
核电厂作为特殊企业,对职工的培训尤为重要,而培训中,仿真系统是必不可少的环节。强果用经典的点堆模型方程,仿真精度不够,不能实现物理仿真。本文利用因子分解方法解中子通量密度函数,在求解中子通量密度形状函数量,通过适当的模型简化,使其可以在一般的PC机上实现。 相似文献
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《Journal of Nuclear Science and Technology》2013,50(5):406-411
The improved coarse mesh method, which was originally derived by Askew and extended by Takeda, has been modified and applied to a 1,000-MWe and a 300-MWe homogeneous FBR core. In the present method, mesh average neutron flux and mesh center neutron flux are distinguished, and transverse neutron bucklings are taken into account. The results of numerical calculations showed that, with the present method, the power distribution and CR worths are appreciably improved for the 1,000-MWe FBR core with large-pitch fuel assemblies. When CRs are withdrawn, the use of the present method reduces the error of power distribution by half for both cores. However, it yields less satisfactory results, particularly with repect to CR worths, for the 300-MWe FBR core with small-pitch fuel assemblies. 相似文献