西安脉冲堆带核调试试验

介绍了西安脉冲堆带核调试试验内容，给出了稳态堆芯、脉冲堆芯及72小时额定功率运行试验堆芯的反应性和中子注量率等参数的测量结果。测量结果证明，西安脉冲堆性能参数达到了设计指标，并为该堆的运行提供了必不可少的运行参数。     

西安脉冲堆热工水力分析与脉冲特性分析

利用PRTHA、PULSE和TEMPUL程序分别计算了西安脉冲堆首循环稳态堆芯布置的热工水力参数和脉冲堆芯的脉冲参数.计算结果表明,西安脉冲堆的传热是安全的.     

西安脉冲堆稳态堆芯脉冲运行安全性分析及新堆芯布置方案设计

通过对堆芯安全参数的理论计算,分析了西安脉冲堆稳态堆芯布置脉冲运行的可行性.在原设计稳态堆芯的基础上,给出两种新的堆芯布置方案,计算了两种设计方案的堆芯物理参数、安全参数和孔道参数.该项工作对今后简化例料程序、提高特定孔道参数、降低燃料元件破损事故发生概率具有一定的意义.     

用脉冲源技术测量脉冲堆的反应性

一、引言 对于一个新型堆,在其正式投入运行之前,反应性的测量十分重要。本工作的主要任务是在脉冲堆首次零功率物理实验中测量其反应性,以验证堆芯设计参数。校核理论计算,探讨运行和实验技术,指导脉冲堆首次物理启动实验的安全运行,为脉冲堆正式投入运行提供实验参数。全部工作于1989年10月结束。     

脉冲堆事故分析

本文介绍了脉冲堆两个最大假想事故——堆水池失水并使堆芯裸露和脉冲棒误发射事故分析结果。对于堆水池失水并使堆芯裸露事故,只要能及时停堆,无需采取任何其他措施,则能保证反应堆的安全。事故过程中,燃料芯体和包壳温度都不会超过840℃。在稳态额定功率下脉冲棒误发射事故过程中,反应堆峰功率达4800MW,燃料温度峰值为950℃,反应堆也是安全的。     

我国第一座脉冲反应堆

我国第一座脉冲反应堆是座小型池式研究堆,采用铀氢锆(UZrH_(1.6))燃料-慢化剂粗棒元件。堆芯靠轻水自然循环冷却,石墨作反射层。该堆具有很大的瞬发负温度系数,不仅能稳态运行,而且还能进行独特的脉冲运行和方波运行。稳态运行额定功率1000kW,堆芯平均热中子通量1.4×10~(13)n/(cm~2·s),当引入3元(2.1×10~(-2)△K/K)瞬发正反应性脉冲运行时,峰功率约为3420MW,中子通量峰值约为6×10(16n)/(cm~2·s)。固有安全、经济及多功能是该堆型最显著的特点。本堆已于1990年7月22日达到首次临界,尔后开始试运行。     

脉冲反应堆脉冲运行瞬态的子通道分析

为获得脉冲运行瞬态的堆芯温度场变化情况,本文开发了适用于低温、常压工况的脉冲反应堆瞬态热工分析子通道程序PRC-STAC。利用TRIGA MARKⅡ反应堆的瞬态参数对程序进行了验证,验证结果表明,二者符合较好。利用PRC-STAC程序计算了西安脉冲堆燃料元件和堆芯冷却剂的瞬态热工参数,并讨论了脉冲运行对燃料元件的安全影响。     

脉冲堆热工水力设计

本文介绍了我国第一座脉冲堆热工水力设计。分析结果表明,该堆具有良好的稳态特性和脉冲特性:在iMW稳态工况下,堆芯最小偏离泡核沸腾比MDNBR为3.28,燃料芯决最高温度为480℃,热通道出口水温不超过95℃;在引入瞬发3.5元正反应性脉冲工况下,仍能保证反应堆安全。     

西安脉冲堆反应性引入事故瞬态安全特性分析

为研究西安脉冲堆（XAPR）在意外引入反应性且停堆系统失效事故下的瞬态安全特性,本文基于XAPR的结构和运行特点,建立了适用于XAPR的瞬态热工水力分析模型,并开发了用于XAPR安全特性分析的瞬态热工水力程序TSAC-XAPR。利用TSAC-XAPR程序对反应性引入事故进行模拟计算,结果表明：当XAPR在额定功率范围内运行时,发生反应性引入事故后,堆芯能依靠自身的固有反馈机制使脉冲堆重新达到稳定运行状态;当运行功率过高尤其是超过临界值时,反应性引入事故将导致脉冲堆关键热工水力参数发生振荡,无法再次达到稳态。此外,不同反应性引入方式将影响堆芯参数在反应性引入过程中的变化趋势,但并不影响其最终稳态值。     

脉冲棒驱动机构及其调试

脉冲棒驱动机构是脉冲堆的一个关键运动设备,是承担脉冲堆脉冲运行的执行机构,同时也可用于稳态运行,在反应堆运行后期还兼作补偿棒驱动机构。 该机构采用气-电联合驱动,气动机构用于脉冲发射,电机减速传动机构用于调节脉冲行程和稳态提棒。本文对该机构的结构特点、运行特性和运行原理作了简要的说明,并介绍了机构装堆后的调试程序和调试结果。     

线性子链法在脉冲中子活化计算中的应用

核聚变装置大多在脉冲工况下运行,不同的脉冲运行模式会对材料活化计算产生影响,脉冲的处理方法以及活化计算方法的选择直接决定了计算结果的精度。本文采用线性子链法和解析解公式计算反应链中各核素的数量随时间的变化情况,并通过回溯算法搜索所有参与计算的反应链。针对脉冲中子活化问题,将真实脉冲通过稳态（SS）方法、等效稳态（ESS）方法、连续脉冲（CP）方法进行等效处理,从而简化计算过程,并在此基础上编制了用于脉冲中子活化计算的TACT程序。最后基于天然Fe活化基准题,根据惯性约束聚变装置（IFE）和磁约束聚变装置（MFE）的典型脉冲周期对TACT程序进行测试计算,比较了各种脉冲处理方法的准确度。结果表明：对于IFE和MFE的典型脉冲运行模式,以ESS为前段的CP方法的准确度均优于其他方法;对于CP方法,只需适当保留末尾的真实脉冲数即可达到一定的精度。     

Application of Polarity Correlation Method to Graphite Moderated Reactor

The polarity correlation method has been applied to an experiment for measuring the prompt mode neutron decay constant of a reactor with a long neutron lifetime. Measurements have been performed in the SHE VIII-l at critical and several subcritical steady states (0~ — 1$).

The analog signal of detector output is converted to a polarity signal having only one-bit of information on the amplitude of the detected signal. The polarity correlation function is obtained as the correlation function between two polarity signals. Attention has been paid in the design of the correlator to obtain ample stability in operation. Using a digital computer, the prompt mode neutron decay constant is determined with 2% experimental accuracy from the decay curve of the polarity correlation function. A series of the prompt mode neutron decay constants is fitted to an approximated expression of inhour equation to obtain βl. The value of each prompt mode neutron decay constant was found to be in good agreement with that measured by the pulsed neutron technique. The polarity correlation method is particularly applicable to critical or near critical state where a pulsed neutron source cannot be effectively introduced.

In Appendix, an estimation is made for the error in the measured polarity correlation function due to unbalanced mean setting level in the experiment.     

Self-Limiting Power Excursion Characteristics of Light Water Reactor, (VI)

The theoretical analysis code named REACT, devised for covering pulsed operation of the HTR, is based on a two-point kinetic model, one point representing the average of the core, while the other is optional (e.g. hottest spot). The behavior of reactor power and other parameters are calculated by the average point, and the temperature of the hottest spot by the other point at same time.

Improvements were brought to the code based on experimental data, and good agreement was found between calculation and experimental results obtained for pulsed operation. The feedback reactivity due to the Doppler effect was comprehensively evaluated by recalculation of experimental data; the void behavior was also investigated.     

我国第一座脉冲堆稳态运行试验

本文简要地介绍了我国第一座脉冲堆稳态运行试验方法和设施,给出了冷态和热态以及不同功率下的临界棒位,并给出了反应性、中子通量、功率系数、平衡氙毒和碘坑的测量结果,提供了一批有价值的工程试验数据。本堆实现了1MW 稳态功率运行,进行了连续72小时满功率运行,对反应堆的控制、保护、测量仪器及各系统和设备进行了考验。试运行结果表明:本堆性能良好,各项指标均已达到了设计要求。     

177燃料组件堆芯反应堆机械补偿控制策略研究

177燃料组件堆芯反应堆通常采用G模式运行,负荷跟踪期间需要调整堆芯硼浓度。受硼回收系统能力限制,仅在85%寿期内具备负荷跟踪能力。为改善177燃料组件堆芯反应堆负荷跟踪能力,扩大可进行负荷跟踪的寿期范围,基于177燃料组件堆芯进行了机械补偿控制策略的研究。设计了不同控制棒组布置方案,从控制棒组价值、对功率峰的影响、负荷跟踪过程中控制能力等方面进行了分析。基于优化的控制棒组布置方案和机械补偿控制策略,进行了全寿期基负荷运行、90%寿期末日负荷循环负荷跟踪以及启动过程模拟。结果表明,在适当的控制棒组布置方案下,177燃料组件堆芯可实施机械补偿控制策略,负荷跟踪能力达到了国际先进水平。      

Method of experimental estimation of the effective delayed neutron fraction and of the neutron generation lifetime in the IBR-2 pulsed reactor

Experimental investigations of random fluctuations in the power of the IBR-2 periodic pulsed reactor carried out in the steady-state mode of its operation and in the pulsed mode made it possible to obtain estimations of the main parameters of the kinetics – the effective fraction of delayed neutrons and the average lifetime of prompt neutrons. Functionals were measured relating the main parameters of the kinetic behaviour: the prompt neutron decay constant (steady-state mode) and the relative dispersion of pulse energy fluctuations. It was shown that the experimental values of parameters of the kinetic behaviour are close to the calculated ones. In addition, the power of the spontaneous neutron source was estimated on the basis of the analysis of neutron noise.     

ABSTRACTS OF 1994 AESJ AWARDS

Phenomenological experiments were performed on a 2-dimensional scaled model of the two-region designed pebble-bed high-temperature gas-cooled reactor core consisting of the distinct fuel pebble region and graphite pebble region. Issues with respect to the feasibility of the two-region design, including the establishment of the two-region arrangement, the mixing zone between the two regions, and the stagnant zone existence, were investigated. Three equilibrium conditions were proposed to evaluate the stable tworegion arrangement formation. The general characteristics of the flow of the pebble bed were analyzed on basis of the observed phenomenon. It was found that a stable two-region arrangement was formed under the experimental conditions: the pebbles' motion was to some extent random but also confined by the neighbors of pebbles so that the mixing zone is constrained to a reasonable size. Guide plates utilized to improve mixing are proved to be effective without noticeable effect on the two-region arrangement features. Stagnant zones were observed under the experimental conditions and they were expected to be avoided by improving the design of the experimental setup.     

六角形布置反应堆高保真物理计算方法研究与验证

俄罗斯商用压水堆VVER和大多数实验堆均采用了六角形紧凑型栅格布置,为了实现VVER和六角形实验堆的高保真数值模拟分析,本文基于数值反应堆物理计算程序（NECP-X）开展了六角形堆芯高保真计算方法研究和程序开发。首先,将全局-局部耦合共振自屏计算方法拓展至六角形堆芯,实现六角形堆芯燃料棒的全堆芯高精度共振计算;其次,基于2D/1D耦合输运计算方法研究了六角形堆芯的高保真计算方法;最后,为了提高全堆芯计算的计算效率,研究了基于区域分解松耦合的非结构网格的粗网有限差分（CMFD）加速方法,可以实现以矩形、六角形和其他多边形栅元为基础的pin-by-pin CMFD 加速。为了验证六角形堆芯高保真计算方法的精度和效率,计算了六角形C5G7基准问题,并分析了六角形输运计算方法的计算精度和CMFD方法的加速效果;将NECP-X程序应用于西安脉冲堆的2D全堆芯计算,与蒙特卡罗程序的结果对比表明NECP-X程序计算得到的特征值和功率分布均具有较高精度。因此,本文建立的六角形堆芯高保真计算方法可以应用于六角形堆芯的分析计算。