轻水堆核电站奥氏体不锈钢铸件的热老化及其老化管理

在轻水堆核电站中,奥氏体不锈钢铸件(CASS)在运行温度下长期工作将面临热老化问题。本文对热老化的机理进行了描述,并针对核电站的热老化问题,给出了老化管理工作的主要步骤,即部件敏感性甄别、老化状态评估和ISI大纲更新;结合CASS热老化的老化管理实践,对我国核电站的热老化管理工作提出了建议。     

核电用铸造奥氏体不锈钢的热老化性能研究

压水堆核电厂主管道用国产铸造奥氏体不锈钢(CASS)长期服役会面临着热老化问题。在400℃高温下开展CASS材料的加速热老化实验,采用夏比冲击试验获得了材料室温吸收能量随热老化时间延长的下降规律,采用扫描电镜观察到不同热老化时间冲击断口形貌的变化趋势。实验结果表明:经过15 000h的加速热老化实验,CASS材料的热老化程度逐渐达到饱和状态,吸收能量虽大幅下降,但仍能满足设计规范对CASS材料在未老化状态时的考核要求。     

CF-8M铸造不锈钢主管道的热老化脆化行为研究

为了评价和预测铸造奥氏体不锈钢(CASS)材料服役期限内的热老化脆化程度，通过对美国的阿贡实验室(ANL)预测模型的研究和分析，以及在400℃下对核级CF-8M主管道材料实施了10 000 h的加速热老化试验，研究了CF-8M材料在不同热老化时间下拉伸性能、冲击性能和微观组织的变化规律，以冲击能作为表征热老化脆化程度的参数，获得了CF-8M材料的热老化脆化预测关系式，并与ANL模型的预测结果进行了对比和分析。结果表明，在加速热老化试验周期内随着热老化时间的增加，CF-8M材料的室温和高温(350℃)0.2%塑性延伸强度变化缓慢，抗拉强度缓慢增加；室温冲击能迅速下降，8 000 h以后冲击能下降趋势接近饱和状态；ANL模型对试验对象在加速老化试验周期内的冲击能预测结果不保守。CF-8M材料加速热老化10 000 h即等效服役30.49 a,其热老化脆化程度接近于热老化饱和状态。     

316LN奥氏体不锈钢焊缝低温热老化行为研究

在压水堆核电厂中,主管道奥氏体不锈钢焊缝长期在其热老化敏感温度(280~325℃)下运行,为了研究主管道奥氏体不锈钢焊缝在核电厂运行温度下的热老化性能,开展了铁素体含量为10.7%的316LN不锈钢主管道焊缝在325、365、400℃下的低温热老化行为研究。结果表明:经6000 h热老化后,焊缝中铁素体相和奥氏体相中的主要元素含量没有发生明显变化,焊缝显微硬度快速增加但奥氏体相显微硬度没有发生变化,焊缝冲击功显著下降、拉伸性能变化较小。     

高温及γ辐照老化对改性钠基膨润土影响的初步研究

为了确认高温及γ辐照对改性钠基膨润土的影响.以内蒙古高庙子改性钠基膨润土为研究对象,利用X射线衍射仪和同步热分析仪分析了高温热老化、γ辐照老化和γ辐照-热程序老化作用对改性钠基膨润土性能和微观结构的影响.发现单纯热作用或单纯的辐照作用影响较小,而辐射-热程序老化作用会显著影响改性钠基膨润土的微观结构.经过1000 kG...     

VVER-1000型反应堆压力容器热老化分析评估

本文系统介绍了VVER-1000型反应堆压力容器(RPV)的温度监督情况,针对田湾核电站1#机组RPV的温度监督测试结果进行分析,评价运行3年后RPV力学性能(包括拉伸、冲击、断裂韧性)变化行为及热老化脆化机理,评估了当前田湾RPV服役运行后的热老化脆化状态和温度监督的时间安排。结果表明,温度监督样品经过堆内高温环境考验后,焊缝材料表现出一定程度的脆化特征,但母材、热影响区脆化不明显。与康采恩模型的结果和俄罗斯数据相比较后,认为田湾核电站1#机组RPV热老化脆化情况在合理范围内。     

聚醚聚氨酯泡沫塑料的辐射老化研究

研究了经电子束作用后聚醚聚氨酯(ETPU)泡沫塑料的辐射老化规律。采用气相色谱(GC)、热分析(TG)、扫描电镜(SEM)和透射电镜(TEM)技术，研究了材料经辐照后其辐解气体产物的种类和生成量以及材料的热性能、微观相分离和表观形貌的变化。     

核电厂主管道90°弯头热老化程度的评估

根据IAEA和国际上相关文献提出的铸造奥氏体-铁素体不锈钢热老化评价方法和评估流程,以秦山核电厂二期扩建工程为例,对静态铸造奥氏体-铁素体不锈钢主管道90°弯头在长时间热老化后,以及在325℃服役10 a后的冲击韧性和断裂韧性J-R曲线进行评估。评估结果表明:秦山核电厂二期扩建工程主管道静态铸造奥氏体-铁素体不锈钢主管道90°弯头在325℃服役10 a后的冲击韧性和断裂韧性有明显的下降,但冲击韧性仍在安全裕量以内,长时间热老化后的冲击韧性已低于设计要求。     

Z3CN20.09M奥氏体不锈钢热老化冲击性能试验研究

采用GB/T19748-2005钢材夏比V型缺口摆锤冲击试验仪器化试验方法,对压水堆核电厂用离心铸造Z3CN20.09M奥氏体不锈钢主管道样品进行了实验室热老化的冲击性能研究。冲击试验数据的统计分析表明,热老化对Fiu/Fm比值不产生影响,而对冲击载荷有显著影响,对冲击能量的影响则更为显著。透射电子显微分析表明,热老化导致铁素体中出现沉淀物,并引发了奥氏体中位错组态的改变。与热老化时间lg t之间也满足线性关系。     

中子辐照奥氏体不锈钢焊缝热影响区力学性能与微观结构的关系

奥氏体不锈钢通常用来制造核反应堆内部部件（如堆芯围筒）,经中子辐照后,其微观结构发生变化,从而导致力学性能的变化。焊缝热影响区材料在熔焊过程中受到焊接热循环的影响。本文研究了中子辐照对奥氏体不锈钢焊缝热影响区材料微观结构及力学性能的影响。试验材料选用退役压水堆中的AISI304不锈钢焊件。该材料在反应堆中经历了11次反应堆循环,最大辐照剂量为0．35dpa,温度为573K。通过试验得到不同辐照剂量下,热影响区材料和母材区材料的力学性能和微观结构。力学性能通过拉伸实验获得,采用室温和573K两种不同试验温度。用透射电镜观察材料的微观结构。运用弥散障碍硬化模型得到力学性能与微观结构之间的关系。试验结果表明：仅用透射电镜中观察到的中子辐照产生的缺陷并不能很好解释中子辐照硬化。在透射电镜中观察不到的那些小的辐照缺陷也能产生辐照硬化。     

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。     

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％.     

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.     

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.     

秦山核电厂放射源管理经验

秦山核电厂对放射源管理有一套系统的制度，从原的申购，入库，保管，使用，报废，到存入专门的废物库这一全过程实施了严格的控制管理，保证了放射源的安全。本文介绍了秦山核电厂在放射源管理的制度建设，保管使用，监督检查和过程控制等方面的经验。