可携式荧光素钠气溶胶发生器样机研制

荧光素钠法是高效粒子空气过滤器现场试验的重要方法之一，荧光素钠气溶胶发生器是该方法的核心设备，本文介绍了我们研制的一台可携式荧光素钠气溶胶发生器样机的结构，性能测试方法和技术指标。以及该样机与两台法国产发生器的对比测试结果，样机的平均质量发生速度32．9mg/h，质量中值直径0．22μm，几何标准差1．58，在平均发生速率时对风量不超过150000m^3/h的过滤系统的可测过滤效率不低于99．99％，样机的重量为25kg，便于核设施通风过滤系统的现场试验。     

固态气溶胶吸湿生长对过滤器检测效率的影响

本文使用加湿串联差分迁移分析仪（HTDMA）系统,研究了荧光素钠气溶胶在不同相对湿度（RH）环境中粒径的变化规律及对现场过滤效率的影响,且与NaCl气溶胶进行了对比。研究结果表明,荧光素钠气溶胶无潮解点,其粒径随相对湿度的增大而增大;NaCl有明显的潮解点,在小于75%相对湿度时,其粒径基本不变。随相对湿度的增加,直径为100 nm的荧光素钠测得的效率逐渐降低,而直径为100 nm的NaCl测得的效率在75%相对湿度以下时基本保持不变,但在大于75%相对湿度环境中大幅下降。因此,从气溶胶吸湿性能的角度来说,作为现场检测用的固态气溶胶,若保证环境相对湿度小于75%,NaCl和荧光素钠均可用于过滤器现场检测,且前者性能优于后者,但当相对湿度大于75%时,NaCl气溶胶已不能用于现场检测用途。     

荧光素钠试验方法与试验装置

荧光素钠法是核级高效空气过滤器现场试验的重要方法之一.本文对其原理、数据记录和处理以及研制的荧光素钠气溶胶发生装置进行了介绍.近几年的实践证明,该装置安全可靠、有效,可进一步推广.     

荧光分光光度法测定水中示踪剂荧光素钠示踪剂

采用荧光分光光度法对水中示踪剂荧光素钠进行检测。在激发波长为492 nm,发射波长为513 nm时,荧光素钠溶液的荧光值最大。溶液pH值对水中荧光素钠的荧光值测定影响较大,且用硼砂pH标准溶液调节水样的pH效果最佳。在0～1.6 mg·L-1的浓度范围内,荧光素钠含量与荧光值呈良好的线性关系。荧光分光光度法对水中示踪剂荧光素钠的检测具有良好的准确度和精密度,其检出限为0.000 15 mg·L-1。该方法适用于海水、自来水、地下水与地热水等水中示踪剂荧光素钠含量的测定。     

微机控制的钠回路中钠温度及流量巡迴检测装置

一、前言本系统用于检测和控制钠化学回路中钠的温度和流量。实验中钠回路的运行温度一般在400℃左右。准确及时地检测钠的温度和流量是保证钠回路安全运行的重要环节。以往钠回路一直采用仪表控制,并且存在误差大、不能直接进行数据处理和体积大等缺点。这套巡迴检测系统的研制,在实现自动检测方面做了有益的尝试。     

一回路流量变化时CEFR停堆保护特性的研究

为了对目前CEFR反应堆设计中的安全裕度进行研究,通过simulink建立钠冷快堆CEFR的热工模型.采用反应堆安全分析中的预期瞬态无停堆保护的方法,对其一回路发生流量变化时反应堆的状态进行仿真分析,并确保在整个事故过程中反应堆状态符合钠冷快堆事故验收准则的要求.仿真结果表明,当一回路流量发生变化时,反应堆在整个过程中...     

高效过滤器现场试验荧光素钠法中采样滤膜的性能研究

根据荧光素钠法的采样要求,建立了以荧光素钠为气溶胶介质的采样滤膜性能测试装置和方法,实测了7种玻璃纤维滤膜的阻力、本底荧光值及流速0.92~2.75 m/s下的过滤效率,并分析了各种滤膜性能对过滤器净化系数检测结果的影响。结果显示,滤膜本身过滤效率对高效过滤器系统净化系数的影响较小,其中的CF-A、FP5211、GC90滤膜的相对误差分别为0.014%、0.063%、0.082%;浸泡液浓度较低时,本底荧光值对系统净化系数的影响比较明显;而阻力过大限制了滤膜上荧光素钠的收集量,进而相对增加了本底荧光值的干扰。研究结果可以为采样滤膜的评价、选择、使用提供指导。     

CEFR一回路管廊通风系统改造后雾状钠火事故分析

中国实验快堆（CEFR）是液态金属钠冷却的快中子实验堆,一回路钠净化系统管廊即309/1房间作为放射性钠气溶胶包容小室之一,房间内布满高温涉钠管道,特别是布置了反应堆主容器内高温强放射性钠流向外部的唯一管道。假使管道破裂,SSW喷射出的高温钠会燃烧引起钠火,在一定条件下,可能会产生持续的雾状钠火,对于房间压力、房间内气体温度、内部结构温度等因素影响很大。基于给309/1房间降温的目的对该房间进行了通风系统改造,改造后的通风系统增大了在309/1房间的正常排风量和正常进风量,这应该会对309房间的钠火事故热力学后果有所影响。本文利用FEUMIX程序计算一回路管廊通风系统改造后发生的雾状钠火事故后果,并与原通风设计条件下的雾状钠火事故后果进行对比,结果表明,通风系统改造对一回路管廊的雾状钠火事故具有一定缓解效果。     

基于Labview的相关法测量钠流量系统设计

为满足中国实验快堆(CEFR)一回路主泵旁路钠流量计校准的需求,设计了1套基于Labview软件的相关钠流量测量系统。本文介绍了相关法的测量原理、设计的相关钠流量测量系统、对该系统的仿真试验和钠回路上的验证试验。试验结果表明,这套基于Labview的相关钠流量测量系统是可行的。本文还进行了该系统的测量误差分析,给出了减小误差的方法。该系统及其试验为CEFR一回路主泵旁路钠流量计在役校准装置的设计、调试和运行提供了依据。     

一种通风流量孔板光圈调节器的研制

水-水反应堆（WWER）机组核岛通风系统调试时,采用固定流量孔板进行风量调节,存在操作量大、耗时长的问题。通过对光圈机构原理进行解析,研制了一种通风流量孔板光圈调节器。测试结果表明,调节器实现了在线改变通径进行风量调节的功能,且具有易安装、精度高的特点。该装置用于系统调试,避免了固定通径孔板的反复变更,有利于提高调试效率,同时也为其他堆型通风系统的设计提供了借鉴和参考。      

两相流动稳定性的系统辨识

叙述了用相关分析系统辨识方法判别两相流动不稳定性的原理、实验方法及测试结果。该方法将信息科学中的系统稳定和系统辨识理论应用于热物理科学中的两相流稳定性研究，发展了新概念的两相流稳定性实验技术和方法。该方法使得在稳定工况下判别两相流系统的不稳定边界和稳定裕度成为可能。实验是在低温堆热工水力学模拟实验系统ＨＲＴＬ－５上进行的，实验中以加热功率的逆重复伪随机序列做为输入信号源，系统流量作为响应函数，用相关分析研究了两相流动系统自然循环的稳定性和稳定裕度。实验结果证明系统辨识方法判别两相流动稳定性是成功的。该实验结果对确立两相流动态数学模型，验证理论模型对稳定边界的判别提供了基础数据。对发展系统分析和状态监视方法，对建立工程系统中两相流不稳定性预报方法具有一定学术和实用参考价值。     

反应堆冷却剂系统流量测量试验研究与设计

华龙一号（HPR1000）设置了反应堆冷却剂泵进出口压差表用于测量反应堆冷却剂系统（RCS系统）环路流量,取消了二代改进型核电机组设置的弯管流量计。环路流量测量方式的改变直接影响RCS系统流量测量试验的实施。通过研究主泵的运行特性和系统的阻力特性,提出了基于主泵电功率测量RCS系统流量的试验方法。结合理论分析结果和工程实践经验,给出了反应堆冷却剂惰走流量试验的试验方法和验收准则。研究表明,主泵电功率法可以测量RCS系统的流量,反应堆冷却剂惰走流量可以通过主泵惰转过程的转速变化进行验证。      

仪用压缩空气SAR001MD涡轮流量计故障分析及处理

反应堆厂房入口仪用压缩空气流量计SAR001MD作为核电站重要监测仪表之一,流量数据的准确性关系到机组的安全运行。一旦出现故障必须予以高度重视,及时解决。某核电站CPR1000机组,在1号机组状态首次即将进入临界阶段时,出现SAR001MD流量计大幅度波动现象,导致安全壳泄漏率监测系统不可用,机组状态停滞。     

A study of the critical flow models used in reactor blowdown analysis

Two-phase critical flow models widely used in safety calculations are compared with extensive published experimental measurements of the choked flowrates of steam-water mixtures. Comments are made on the applicability of the models in their supposed regions of validity and a mathematical upper limit to discharge flowrate is derived. The data fall below this limit and generally above a homogeneous isentropic flow model in thermal equilibrium. Suitable measurements of critical flowrates in pipes of diamater in the range of direct relevance to reactor blowdown calculations are still unavailable.     

CPR1000机组低压安注泵流量校核试验不满足准则时的分析

中国改进型三环路压水堆（CPR1000）低压安注系统（LHSI）泵流量校核试验不满足验收准则时,需要对管路系统中的限流孔板进行调整。通过工程流体力学计算分析,可以得到各种条件下限流孔板的调整方法。应用该分析方法,可以准确地得到满足LHSI运行要求的限流孔板尺寸。该分析方法有效地解决了在低压安注泵流量校核试验不满足准则要求时,如何对管路系统中限流孔板进行更换的问题。      

秦山核电厂设备冷却水系统流量分配试验

本文介绍了秦山核电厂设备冷却水系统流量分配试验。叙述了试验目的、试验条件、试验内容及其方法。提供了系统多种运行工况下的试验数据。试验结果表明,系统能正常运行,满足电站运行要求。     

Development of natural circulation analysis methods for a sodium cooled fast reactor

A natural circulation evaluation methodology has been developed to insure safety of a sodium cooled fast reactor (SFR) of 1500 MWe adopting a natural circulation decay heat removal system (NC-DHRS). The methodology consists of a one-dimensional safety analysis which can be applied to safety evaluation for SFR licensing taking into account the temperature flattening effect due to buoyancy force in the core, and a three-dimensional fluid flow analysis which can evaluate thermal-hydraulics for local convection and thermal stratification in the primary system and DHRSs. The one-dimensional safety analysis method and the three-dimensional fluid flow analysis method have been validated using the test results of a water test apparatus and a sodium test loop for some typical transient events selected from the design basis events of the SFR. Finally, it has been confirmed that a good agreement between the test results and analysis results has been obtained, and reliability of each method has been demonstrated.     

An integral effect test of a complete loss of reactor coolant system flow rate for the SMART design using the VISTA-ITL facility and its simulation with the MARS-KS code

An integral effect test was successfully performed to provide data to assess the capability of the system analysis code to simulate a complete loss of reactor coolant system (RCS) flow rate (CLOF) scenario for the SMART (System-integrated Modular Advanced ReacTor) design. The steady-state conditions were achieved to satisfy initial test conditions presented in the test requirement, its boundary conditions were accurately simulated, and the CLOF scenario in the SMART design was reproduced properly using the VISTA-ITL facility. The natural circulation flow rate in the RCS was about 12.0% of the rated RCS flow rate and the flow rate in the passive residual heat removal system (PRHRS) loop was about 10.6% of its rated value in the early stage of the PRHRS operation. In this paper, the major experimental results of the CLOF test are discussed. The test results were analyzed using the best-estimate system analysis code, MARS-KS, to assess its capability to simulate a CLOF scenario for the SMART design.     

Plan for first phase of safety demonstration tests of the High Temperature Engineering Test Reactor (HTTR)

Safety demonstration tests using the High Temperature Engineering Test Reactor (HTTR) will be conducted for the purpose of demonstrating inherent safety features of High Temperature Gas-cooled Reactors (HTGRs) as well as providing the core and plant transient data for validation of HTGR safety analysis codes. The first phase safety demonstration test items include the reactivity insertion test and the coolant flow reduction test. In the reactivity insertion test, which is the control rod withdrawal test, one pair out of 16 pairs of control rods is withdrawn, simulating a reactivity insertion event. The coolant flow reduction test consists of the partial loss of coolant flow test and the gas circulators trip test. In the partial loss of coolant flow test, primary coolant flow rate is slightly reduced by control system. In the gas circulators trip test one and two out of three gas circulators are run down, simulating coolant flow reduction events. The gas circulators trip tests, in which position of control rods are kept unchanged, are simulation tests of anticipated transients without scram (ATWS).     

Scaling of passive condenser system for separate effect testing

The passive containment cooling system (PCCS) of the simplified boiling water reactor (SBWR) is a passive condenser system designed to remove energy from the containment for long term cooling period after a postulated reactor accident. Depending on pressure condition and noncondensable (NC) gas fraction in drywell (DW) and suppression pool (SP), three different modes are possible in the PCCS operation namely the forced flow, cyclic venting and complete condensation modes. The prototype SBWR has total of six condenser units with each unit consisting of hundreds of condenser tubes. Simulation of such prototype system is very expensive and complex. Hence a scaling analysis is used in designing an experimental model for the prototype PCCS condenser system. The motive for scaling is to achieve a homologous relationship between an experiment and the prototype which it represents. A scaling method for separate effect test facility is first presented. The design of the scaled test facility for PCCS condenser is then given. Data from the test facility are presented and scaling approach to relate the scaled test facility data to prototype is discussed.