CEFR事故余热排放系统优化设计

为提高快堆管道设计的经济性,根据支吊架优化原则,对事故余热排放系统进行优化设计,使管道系统在各种预期的载荷工况下,都能满足ASME设计规范规定的应力限值,并减少阻尼器、弹簧支吊架的使用量。通过对CEFR的事故余热排放系统的优化设计,积累了高温管道支吊架的布置经验,为以后快堆的管道设计打下基础。     

中国实验快堆2019年度运行年报

<正>中国实验快堆(CEFR),热功率为65 MW,试验发电功率为20 MW,首炉燃料使用UO2,采用堆本体池式结构和钠-钠-水三回路主热传输系统,并首次设立独立的非能动事故余热排出系统。2019年度CEFR未发生上级别运行事件,未造成设备损坏和放射性释放,实现全年安全稳定运行。     

中国实验快堆空气热交换器热工流体力学研究

事故余热排放系统（DHRS）是CEFR的重要系统，其设计原理是依靠自然对流和自然循环导出事故停堆后的余热。空气热交换器是事故余热排放系统的重要设备，堆芯事故余热最终要通过该设备排入到空气中，空气热交换器的换热情况直接关系到DHRS的自然循环效果和排热能力，从而关系到反应堆的安全。因此，对空气热交换器的热工流体力学特性进行研究是十分必要的。     

中国实验快堆2018年度运行年报

正中国实验快堆(CEFR)热功率为65 MW,试验发电功率为20 MW,首炉燃料使用UO2,采用堆本体池式结构和钠-钠-水三回路热传输系统,并首次设立独立的非能动事故余热排出系统。2018年反应堆处于冷停堆运行状态,继续进行大修遗留工作及大修调试工作,完成系统恢复与功能鉴定,完成3次开堆前检查和常规岛热态运行,对开堆强相关项进行处理和验证,实现冷停堆运行工况下的全厂安全稳定运行。     

CEFR余热排出系统实验验证

CEFR在事故停堆后的剩余功率需通过事故余热排出系统导出。CEFR要求验证在事故余热排出阶段剩余功率≤额定功率的1％（功率分别为 2、3、4、6和 8.5kW）时,堆池内是否还存在有堆芯-热腔室-冷腔室-堆芯这一自然循环流动。此外,通过相应工况下整个热腔室内的温度分布的实验测量,为验证有关计算程序提供实验依据。 由于种种原因的影响,在CEFR的寿期中很可能出现2台余热冷却器中的1台停运的情况,因此工程部要求通过实验提交该工况下的安全性能的验证报告。国外在相关研究中发现,     

中国实验快堆堆芯围桶开孔对正常运行工况影响的分析

堆芯围桶开孔是中国实验快堆(CEFR)事故余热排出系统的重要组成部分之一,是保证该系统形成自然循环排出反应堆事故后剩余发热的关键环节。本文应用通用计算流体力学软件CFX对CEFR堆芯围桶开孔对反应堆正常运行工况的影响进行了模拟,计算了在正常工况运行时,CEFR的反射组件与屏蔽组件热功率对堆芯围桶开孔附近温度场以及流场的影响,给出了堆芯围桶开孔区域的三维温度场、三维流场以及压力分布矢量图。结果表明,目前的设计在满足事故余热排出的要求同时,对反应堆正常运行工况的影响是可以接受的。     

中国实验快堆超功率瞬态分析研究

在核电厂的安全分析中,系统程序能够对多种事故瞬态进行瞬态分析。随着我国快堆技术的发展,在快堆系统程序的开发和应用等方面也做了一些工作。本文运用法国原子能委员开发的快堆系统分析程序DYN4G建立了中国实验快堆(CEFR)的系统模型,包括堆芯、一回路、二回路、汽水回路和事故余热排出系统,并计算了满功率下的稳态,与设计值进行了比对,同时完成了超功率事故的瞬态分析,并与《CEFR最终安全分析报告》中的计算进行了对比验证。计算结果表明程序能较好的模拟CEFR的稳态和超功率情况,为进一步开展CEFR的安全研究及钠冷快堆的安全分析打下了基础。     

CEFR非对称运行工况的研究

为研究中国实验快堆（CEFR）非对称运行工况,通过快堆系统安全分析程序OASIS及堆芯子通道分析程序COBRA对CEFR单环路运行时堆内的温度以及流量进行了计算。结果表明,CEFR在单环路运行,完好环路一、二次钠泵转速为500 r/min,且事故环路一次钠泵逆止阀开启时,堆芯最多开启在14%的功率水平,以确保反应堆处于安全状态。     

OEFR进口部件与国产管道的焊接件在410℃钠中的腐蚀

中国实验快堆（CEFR）的钠存在信号装置管道材料为俄罗斯进口的12X18H10T，它与国产304L不锈钢的焊接处位于410℃流动钠的运行工况中。另外，CEFR一回路的净化支路电磁泵为意大利PEC堆的电磁泵，电磁泵进出口管的材料为AISI316不锈钢，在系统中与国产304L不锈钢管道相焊接，此焊接件所处环境为410℃流动钠。进口的与国产的不同材料间的焊接件在快堆实际运行工况下与钠的相容性如何，是否会发生晶间腐蚀，这直接关系到CEFR部件的安全稳定运行。     

CEFR事故余热排放系统部分管道应力分析

本文通过Pipestress软件计算事故余热排放系统有关管道,合理布置管道支吊架系统.使管道系统在各种预期的载荷工况下,均能满足ASME设计规范规定的应力限值,并满足机械设计和现场安装的要求.     

Increase in internal friction in uranium with change in temperature

On the basis of the previously described increase in internal friction in uranium during heating, a semiquantitative evaluation was made of the dependence of increase in internal friction on the rate of heating, frequency and amplitude of vibrations. The results of the calculations agree satisfactorily with data obtained experimentally. A study was made of the effect of the initial state of the specimen on the increase in internal friction at the initial stages of heating.     

广东省进出口食品中的放射性检验

报道了广东省商检中心放射性检验室开展的广东进出口食品中的放射性检验工作。介绍了检验工作采用仪器的主要性能及应用;给出了分析测量方法和探测下限以及实验的质量保证措施,并给出了检验室测量的广东省几种食品中的放射性含量范围,测量结果与我国食品中放射性活度变化范围大体一致。     

Tritium concentrations in precipitation in Shanghai

Tritium concentrations in precipitation can be used as a criterion to evaluate the tritium baseline of the environment. The tritium concentration in precipitation in Shanghai during 2014-2015 was determined. Values ranged from 0.68 ± 0.04 to 4.11 ± 0.39 Bq/L, and it showed a decreasing trend compared with historical data; however,the values were slightly higher than the natural background tritium level. Additionally, the tritium concentration shows a seasonal variation: It was higher in autumn and winter and lower in summer and spring. A comparison of concentrations in precipitation in Shanghai and around the Qinshan Nuclear Power Plant reveals no correlation,implying that the nuclear power plant operations may not affect the environment of Shanghai. Thus, the raised tritium concentrations in Shanghai might be due to the effects of monsoons, spring leak, raindrop, or other activities that generate tritium there. Those activities may include chemistry research that uses tritium as a tracer.     

微机在核物理实验应用中的抗干扰问题

本文简单介绍了计算机在核物理技术应用中的各种噪声，并初步探讨了抑制噪声的方法。     

Tritium concentrations in precipitation in Shanghai

Beamline BL17 U1 at Shanghai Synchrotron Radiation Facility is an energy-tunable macromolecular crystallography beamline that has been in user operation since 2009. Growing demand from the user community for a small beam and related experimental methods have motivated upgrades of the devices in the endstation.Minibeam modes have already been developed for operation. A self-integrated diffractometer reduces the sphere of confusion of the rotatory axis to 1μm. The new diffractometer is equipped with an upgraded on-axis viewing system that can improve the resolving power. Additionally,the area detector was also upgraded to the newest generation of detectors, the EIGER X 16 M, which can collect data at 133 Hz. After these upgrades, the endstation became virtually new. This paper covers the upgrade of the endstation devices and gives the first data collection results.     

2010年的美国铀矿业

2010年,美国铀矿总共施工7 209个钻孔,总进尺1 493 520 m;生产铀1 628.55t;铀矿业总支出费用为2.773亿美元,其中铀矿地勘费支出为3 450万美元,占铀矿业总费用的12.44％.铀矿地勘钻探费用为4 460万美元,占铀矿业总费用的16.08％.     

我国东南沿海城市地下建筑氡浓度分布

为了解东南沿海城市地下建筑氡浓度的分布，用固体核径迹法(SSNTD’s)，分别在春、夏、冬3季对沿海7城市地下建筑室内氡浓度进行调查。结果表明，福州具有最高的平均氡浓度，上海的平均氡浓度最低。季节的变化对地下建筑室内氡浓度有影响，各城市氡浓度平均值夏季最高、冬季最低。各城市夏季氡浓度与该城市的年均值的比值与城市中各测点氡浓度之间的离散度有一定的相关性。夏季地下建筑室内氡浓度高的城市，它的平均氡浓度受某些具有高氡水平测点的影响大。     

Plutonium use in nuclear power in Russia

Conclusions The following concept of plutonium utilization based on the evolutionary development of the traditional technology in our country arises: The main problem of any short-term program of dealing with plutonium must be solved — reliable and safe storage of separated energy plutonium and freed weapons plutonium before utilization in reactors. Plutonium (mainly energy plutonium) is utilized primarily in BN-800 fast reactors and the development of technology using weapons plutonium in BN-600 reactors starts. In the future attention should be focused on nuclear-power centers patterned after the Industrial Association “Mayak” (RT-1 plant, Complex 300, BN-800) with reliable nonproliferation of weapons plutonium. It is extremely important to speed up work on the completion of Complex 300: This work must be completed before BN-800 is ready. In the future efforts must be concentrated on the following: development and implementation, in BN-800, of an economically more efficient plutonium-burning core; the possibility of building light-water reactors with the required degree of safety for effective plutonium utilization must be justified (including a “cold” core based on cermet fuel); and, development and implementation of technology for a safe and an ecologically acceptable closed nuclear fuel cycle based on plutonium and²³³U with burnout of Am, Np, and Cm. Ministry of Atomic Energy of the Russian Federation. Institute of Physics and Power Engineering. A. A. Bochvar All-Union Scientific-Research Institute of Standardization in Machine Building. Special Design Office for Machines. Translated from Atomnaya énergiya, Vol. 76, No. 4, pp. 326–332, April, 1994.