在拉伸力作用下不锈钢在高温钠中的腐蚀行为

利用自行改进设计的高温钠应力试验装置,研究了316不锈钢及 Cr13Ni17Mo3W 系列不锈钢燃料元件包壳材料在拉伸力作用下的抗高温钠的腐蚀行为。117MPa 以下的拉伸力对材料的抗腐蚀行为没有显著影响。当拉伸力加大到 176MPa 时影响显著。而新研制的 Cr13Ni17Mo3W 系列不锈钢在 600℃ 高温钠中的抗腐蚀性能优于316不锈钢。前者在试验条件下的抗腐蚀性能与 w 含量有关,最佳 W 含量约为2%。     

10MW高温气冷堆压力容器主螺栓液压拉伸机

为了配合１０ＭＷ高温气冷堆３个压力容器的安装与拆卸,清华大学核能技术设计研究院研制了３种主螺栓拉伸机以代替昂贵的进口设备。本文对此拉伸机的研制情况、结构特点、设计参数、试验情况等方面作了描述,并给出螺栓预紧力的计算方法。这批拉伸机已成功地应用于１０ＭＷ高温堆３个压力容器的出厂水压试验。     

Research of Sodium Fire for CEFR

AccordingtothedeficiencyoftheinformationonsodiumfireinChina,aninvestigationreportoninternationalresearchstatusofsodiumfirewasperformed.Itcontainsphysicalandchemicalnatureofsodium,mechanismofsodiumignitionandcombustionprocess,typeandaccidentconsequencespro…     

Material Properties of a Natural UF6 Transport Cylinder Vessel at High Temperature

Abstract

The IAEA Regulations for the Safe Transport of Radioactive Material are to be revised in 1996 and the fire test (800°C for 30 min) could become a requirement for the natural UF₆ transport cylinder. ASME SA 516 carbon steel is used as the structural material for this type of cylinder. It is very important to obtain high temperature data for SA 516 steel to be able to evaluate the integrity of the UF₆ transport cylinder vessel in the fire test. CRIEPI has therefore conducted material tests on SA 516 at high temperatures. The AC₁ and AC₃ transformation points of actual SA 516 steels have been measured. Tensile tests up to 900°C were conducted using USA, French and Japanese manufactured materials and the influence of phase transformation assessed. Preliminary creep tests show that assessment by creep strength can give a more conservative estimation than using the tensile strength. Creep deformation equations have been obtained using uniaxial creep tests and internal pressure creep tests. In addition, by the use of internal pressure creep rupture tests, the relation between the circumferential stress, the test temperature and the rupture time has been obtained.     

从结构热传导角度分析CEFR内钠温度变化速率限值的合理性

CEFR提升功率时要求钠温度变化速率不超过30 ℃/h,为从理论上论证限值30 ℃/h的合理性,通过理论分析和ANSYS软件数值模拟两种方式,研究了介质温度变化条件下平板的非稳态热传导响应过程及平板温度进入稳定状态所需的时间。结果表明,换热条件直接影响结构温度达到稳定状态所需的时间,换热条件好时结构和介质温变基本同步,换热条件差时30 ℃/h的堆内介质温度变化速率能保证介质温度稳定时结构温度达到温变总幅度的60%以上。30 ℃/h钠介质温度变化速率基本使换热条件差的条件下结构温度场进入稳定状态的速率与堆内钠介质温度变化相对同步,降低了温度变化带来的热应力分布和变化的复杂性,基本保证了结构实际温度与稳态设计温度的一致性。     

CEFR整体冷钠池及其辅助系统温度场三维数值模拟

利用流体力学软件CFX对中国实验快堆（CEFR）整体冷钠池及其辅助系统进行详细稳态模拟计算,并验证运行工况下的热工设计。计算结果表明：冷钠池内存在热分层和热分区现象,确实存在冷钠池上板的高温区,同时泵腔室上部的温度较其他区域的高。本工作为反应堆功率提升及运行提供了技术准备。     

Heat Loss Calculation of Reactor Vessel System of CEFR

Because of large temperature difference between atmosphere in reactor pit and the high temperature sodium coolant in China Experimental Fast Reactor（CEFR）, considerable heat loss exists despite of the heat preservation on the reactor surface. For the sake of ascertaining complexion of heat dissipating,     

Analysis on Sodium Void Reactivity Worth of CEFR

It is prepared to do playslcal start-up of CEFR several years late. In order to verity the satety teatures of CEFR＇s core design, the sodium void reactivity worth（SVRW） is necessary to be measured at the stage of physical start-up. This experiment plans to take the test fuel assembly with two heads sealed instead of fuel assembly at the measured location and measure the reactivity worth of capacity formed by the sealed test assembly.     

CEFR钠空泡反应性效应试验测量与计算分析

本文介绍了中国实验快堆物理启动试验中钠空泡反应性效应测量试验的试验程序及测量结果评估,测量结果显示中国实验快堆典型位置钠空泡反应性价值皆为数值较大的负反应性,结果符合试验验证要求,验证了组件瞬间堵流事故专设监测系统的信号基础。并对试验进行了计算分析,试验前的分析为试验提供支持,试验验证了计算分析程序系统。     

High Temperature Sodium Thermal Convection Test Loop

A project for the evaluation of compatibility characteristic of structural materials used in China experimental fast reactor(CEFR) has been in operation. The conditions which these structural materials contact with liquid sodium in reactor can be simulated by the tests in high temperature sodium thermal convection test loop. The main aims of designing and constructing the thermal convection test loop is for the corrosion test of CEFR materials, and the objective is to obtain the corrosion data of domestic materials.The main features of the test loop are shown in Fig.1. The primary components of the loop     

Sodium Spray Fire Calculation and Analysis of the Primary Sodium Purification System of CEFR

The primary sodium purification system is part of the primary coolant boundary of China Experimental Fast Reactor （CEFR）. During the normal operation, the sodium is pumped from the cold pool of the core to the sodium purification system, then the sodium is cooled, decontaminated, reheated and transferred back to the reactor vessel.     

HFETR材料高温辐照试验温度控制技术研究

介绍在高通量工程试验堆(HFETR)中进行高温材料辐照试验的温度控制技术。利用哈氏合金材料辐照试验的测量结果与CFX程序的模拟分析结果进行检验,证明了相关温度控制技术的可行性和有效性。     

高温高压容器封头安装中螺柱应力试验

针对高温高压容器封头法兰连接中,加载后螺柱预紧力分布不均匀问题,提出在螺柱表面粘贴电阻应变片测量螺柱应变变化的测试过程与基本操作方法.采用正弦模型和指数衰减模型预测螺柱应力的变化,以探索适合的预紧方式和制定合理预紧程序.对试验数据的分析结果表明,螺柱的应力沿法兰周向成正弦规律变化;单根螺柱应力在预紧过程中满足指数衰减规...     

High Temperature Corrosion of Iron Chromium Alloys by Tellurium

The reaction rates between iron-chromium alloys (1.17, 5.65 and 11.96 a/0Cr) and tellurium were measured in the temperature range of 873–1,023 K at 350 Pa of tellurium vapor pressure, and in the tellurium vapor pressure range of 66.7–600 Pa at 923 K. The electron probe microanalysis, marker experiment and X-ray diffractometry were employed to clarify the mechanism of the telluride scale growth.

The reaction rates between iron-chromium alloys and tellurium obeyed the parabolic rate law. It was observed that the telluride scale consists of the inner, the intermediate and the outer layers; chromium is concentrated in the inner layer which may grow by the inward diffusion of tellurium; the intermediate layer consists of mainly β-iron telluride, and the outer layer consists of both δ- and δ'-iron tellurides below 980 K, and δ-iron telluride alone above 980 K. The intermediate and outer layers grow by the outward diffusion of iron in iron tellurides.

The protection effect by chromium may be explained by the fact that chromium telluride covered over the surface of iron-chromium alloy interrupts the outward diffusion of iron.

The reaction between iron-chromium alloy and tellurium can be classified into three regions from the view point of the activation energy. From the comparison of the activation energy of the reaction between iron-chromium alloy and tellurium with that for the diffusion of iron in iron tellurides, the rate-determining step for the scale formation for each region was discussed.     

中国实验快堆反应性温度系数理论分析和试验研究

利用CITATION程序对中国实验快堆（CEFR）反应性温度系数进行计算,同时与其他程序计算结果和实验测量值进行比较。CEFR反应性温度系数约为-4 pcm/℃,计算结果与实验值吻合较好。升温和降温过程的反应性温度系数测量误差约为11%,满足试验验收准则。测量结果可校核理论计算结果,同时为CEFR的安全运行和在换料情况下的反应性平衡分析提供参考数据。     

模块式高温气冷堆采用预应力混凝土压力容器的可行性研究

针对模块式高温气冷堆(MHTR)钢制压力容器存在着制造难度大、运输困难和成本高等缺点．开展了对MHTR采用预应力混凝土压力容器(PCPV)的可行性研究本文简要介绍了PCPV的发展现状与技术特点,分析研究了MHTR采用PCPV作为一回路压力边界部件的技术难点及可行性,给出了．MHTR采用PCPV的初步设计方案。对该方案的分析结果表明．将PCPV应用于MHTR在技术上是可行的．不仅能够解决多腔室PCPV的力学问题以及反应堆余热释放等关键技术问题,而且能使MHTR具有更好的安全性和经济性。     

采用组合质量-弹簧模型的快堆卧式贮钠罐晃动分析

在核电工程中广泛使用各类形式的储液容器,储液容器的抗震分析必须考虑液体晃动的影响。针对矩形储液容器,不同于传统的单向质量-弹簧模型将液体晃动对容器侧壁、底部的作用都等效为对侧壁的作用,本文提出一种组合质量-弹簧模型及计算公式,模拟了液体晃动分别对容器的侧壁、底部的作用。组合质量-弹簧模型在三维有限元模型上的加载位置更加合理,容器底部的应力结果更加真实。利用组合质量-弹簧模型对中国实验快堆的卧式贮钠罐进行横向晃动有限元计算,算例表明了计算结果的可靠性。组合质量-弹簧模型为储液容器的有限元抗震分析提供了一种有效的方法。     

中国实验快堆粘钠设备动态去污技术模拟试验研究

采用硫酸和磷酸的混合酸作为去污剂,以530 ℃钠中浸泡3 700 h的304和316不锈钢为试样,进行了快堆设备去污模拟试验,并在去污试验后对试样进行去污深度、微观形貌以及力学性能等分析。结果表明：304和316不锈钢最大去污深度分别可达约10 μm和4 μm;材料去污深度随去污温度、时间、去污剂流速的增加而增大;相同条件下,304不锈钢的去污深度大于316不锈钢。去污后,材料均保持较好的延伸率,抗拉强度略有降低,不影响材料的整体力学性能。以12.5 g/L硫酸和30 g/L磷酸的混合酸一步法去污作为快堆粘钠设备的去污法具有操作简单、去污快、产生废液量少的特点,说明该混合酸是一种高效去污剂。     

10 MW高温气冷堆反应堆压力容器的出厂水压试验

根据ASME规范第Ⅲ卷NB－6200节的规定,对10MW高温气冷堆压力容器的水压试验要求、试验过程、试验结果及评价进行了叙述。用清华大学核能技术设计研究院研制的液压张拉机对主螺栓实施了合理及有效的张拉,对压力容器进行了应变和不变形测量,取得了反应堆压力容器水压试验的圆满成功。