子通道程序与CFD程序的耦合方法研究

随着多种新型堆型的发展,堆芯设计将更加紧凑,为了保证堆芯安全,要求在设计阶段尽可能地精确计算出堆芯内热工参数分布,这就需要针对特定瞬态工况开展堆芯多尺度耦合研究。本文在已有的子通道程序COBRA-EN的基础上,采用动态链接库技术将其耦合到流体动力学程序FLUENT中,开发了适用于堆芯多尺度计算的COBRA-EN/FLUENT耦合程序。进一步通过带腔室的棒束通道算例,分别测试了稳态和瞬态情况下耦合程序的计算精度,结果显示COBRA-EN与FLUENT两者的耦合是有效且可靠的。本研究成果将为新型堆芯的设计和安全分析提供可靠的工具。     

堆芯核设计程序CYCAS动力学模型开发

对堆芯核设计程序CYCAS的动力学模型及其数值验证进行了研究。详细介绍了CYCAS程序采用的动力学模型。为验证模型的有效性,对LMW瞬态基准题和基于AP1000堆芯动态插棒问题进行了数值模拟和分析。结果表明,CYCAS程序的动力学模型可获得可靠的计算结果。     

PWR堆芯不同状况下安全壳内辐射水平的计算

介绍一个用于计算压水堆在正常冷却剂释放、间隙释放和堆芯溶化时安全壳内辐射监测仪表读数值的计算机程序CCRLCC。利用国际原子能机构技术文件中给出的参数输入该程序计算得到的结果和该文件中所给数据进行了比较,从而验证了程序的正确性。应用CCRLCC可以计算在停堆24 h内任意时刻不同堆芯损伤状况下的安全壳辐射监测仪表读数。该程序可以应用于基于安全壳内辐射水平提高的应急行动水平的制定,为事故期间根据安全壳内辐射监测仪表读数确定堆芯损伤状况提供依据。     

Bamboo程序在方形组件压水堆中的适用性验证研究

本文对国产自主化核设计程序Bamboo程序在方形组件压水堆中的适用性开展了研究。主要内容包括：利用Bamboo程序对三种国内典型的方形组件压水堆进行建模,并将堆芯临界硼浓度、堆芯功率分布、堆芯燃耗分布、控制棒价值和反应性系数等参数的计算结果,同堆芯实测结果或SCIENCE程序计算结果进行对比验证。结果表明,Bamboo程序在典型方形组件压水堆堆芯计算中具有良好的精度,能够满足核电厂的堆芯核设计需求。研究结果为Bamboo程序进一步的工程应用奠定了基础。     

严重事故条件下堆芯升温模拟

使用FLUENT计算流体程序数值模拟了AP1000在严重事故条件下的堆芯升温过程,目的是对堆芯裸露后并在其显著熔化前对堆芯升温的均匀程度进行比一体化事故程序MAAP更为详尽的研究,进行围筒和吊篮温度分析,同时评估MAAP程序堆芯升温计算结果。分析结果表明：在堆芯显著熔化时刻,堆芯围筒和吊篮已熔化,因此熔融堆芯将从侧面迁移进入下封头,同时对比证明MAAP程序关于堆芯升温的计算结果也是可接受的。     

大功率压水堆堆芯燃料管理设计

设计了一种大功率压水堆堆芯,对其中可燃毒物装载方案、平衡循环布置、首循环装料及过渡循环方案进行了研究。采用特征统计算法CSA燃料管理优化程序,快速高效地搜索堆芯装载和可燃毒物配置优化方案。采用堆芯核设计程序CPACT进行全堆计算,结果真实可靠。分别设计了18个月和24个月换料两种方案,计算结果表明,在满足堆芯燃料管理所有限值要求的前提下,两种方案均从第4循环开始进入平衡循环。     

高温气冷堆放射性总量计算程序研发与验证

堆芯放射性总量计算是核电站辐射防护设计、屏蔽计算和环境影响评价的基础。为进一步提高高温气冷堆堆芯放射性总量计算分析能力,自主研发了高温气冷堆堆芯源项计算程序NUIT,计算了HTR-10和HTR-PM堆芯内特定燃耗的燃料元件的放射性,并与KORIGEN程序的计算结果进行了对比。计算结果表明,NUIT程序可用于高温气冷堆堆芯放射性总量计算,并具有较好的计算精度和效率。     

高通量工程试验堆堆芯流量分配计算

建立了合理的高通量工程试验堆（HFERT）堆芯流量分配计算模型，并编制了相应的计算程序。应用此程序可以精确计算和分析HFETR堆芯流量分配和温场。经过中国核动力研究设计院提供的实验数据的验证计算表明，本程序计算结果与相应的实验数据符合很好。     

核热推进系统氢气物性及流动换热模型分析

为开展关于核热推进反应堆堆芯的稳态热工水力计算,基于现有针对压水堆的系统分析程序,添加了氢气的物性模型及流动换热和摩擦阻力关系式,并采用公开文献中的数据进行验证。结果表明采用上述模型计算得到的结果与参考值符合较好,二次开发的程序适用于氢气的流动换热计算。针对一种折流式核热推进反应堆堆芯,使用该系统程序建模并计算,得到了堆芯的流量、焓升等分布情况。研究结果表明,对于折流式核热推进反应堆,内外堆芯燃料元件之间的导热会增强堆芯释热不均,对堆芯的稳态热工水力特性有较大影响,堆芯物理方案的设计应结合热工水力方面的计算。本研究可为核热推进系统内氢气流动换热计算提供借鉴。     

核热推进系统氢气物性及流动换热模型分析

为开展关于核热推进反应堆堆芯的稳态热工水力计算,基于现有针对压水堆的系统分析程序,添加了氢气的物性模型及流动换热和摩擦阻力关系式,并采用公开文献中的数据进行验证。结果表明采用上述模型计算得到的结果与参考值符合较好,二次开发的程序适用于氢气的流动换热计算。针对一种折流式核热推进反应堆堆芯,使用该系统程序建模并计算,得到了堆芯的流量、焓升等分布情况。研究结果表明,对于折流式核热推进反应堆,内外堆芯燃料元件之间的导热会增强堆芯释热不均,对堆芯的稳态热工水力特性有较大影响,堆芯物理方案的设计应结合热工水力方面的计算。本研究可为核热推进系统内氢气流动换热计算提供借鉴。     

环形燃料热工水力性能分析程序开发及验证

本工作开发了环形燃料子通道分析程序SAAF。采用SAAF计算了西屋公司四环路压水堆所用环形燃料组件的热工水力性能,并与VIPRE-01的计算结果进行比较。结果表明,SAAF与VIPRE-01的计算结果符合较好,SAAF可用于环形燃料热工水力设计分析。     

钠冷快堆乏燃料组件热工水力分析程序开发

为了对示范快堆乏燃料组件的热工水力特性进行分析,自主研发了钠冷快堆乏燃料组件热工水力分析程序SPATANS。该程序基于子通道分析方法,采用适用于低流量下的流动换热和交混关系式。针对乏燃料组件棒束区进行计算,得到组件不同高度处各子通道的温度、压力等热工参数,并将计算结果与三维计算流体力学FLUENT程序的结果进行对比分析。结果表明：自主研发程序的计算结果与FLUENT程序的计算结果较为吻合,偏差在工程可接受范围内,且其计算效率明显高于FLUENT程序。初步表明SPATANS程序可用于钠冷快堆乏燃料组件热工水力分析,并具有良好的应用前景。     

Valuation of BWR stability operating in natural circulation conditions

Nowadays, new concepts of nuclear reactors have been projected to work with mechanisms of natural circulation (NC). However, NC systems are very susceptible to several kinds of instabilities being necessary careful studies about such systems. In this work, a theoretical investigation about BWR stability during a transient of recirculation pump trip bringing the reactor to operate at NC conditions is presented. The simulations were performed using the RELAP5/MOD3.3 thermal-hydraulic code and the PARCS/2.4 3D neutron-kinetic code in a coupled way to predict the transient results. The power time evolution and the related thermal-hydraulic parameters were investigated during the transient to analyze the behavior of the reactor for this special operation condition of NC.     

Valuation of BWR stability operating in natural circulation conditions

Nowadays, new concepts of nuclear reactors have been projected to work with mechanisms of natural circulation (NC). However, NC systems are very susceptible to several kinds of instabilities being necessary careful studies about such systems. In this work, a theoretical investigation about BWR stability during a transient of recirculation pump trip bringing the reactor to operate at NC conditions is presented. The simulations were performed using the RELAP5/MOD3.3 thermal-hydraulic code and the PARCS/2.4 3D neutron-kinetic code in a coupled way to predict the transient results. The power time evolution and the related thermal-hydraulic parameters were investigated during the transient to analyze the behavior of the reactor for this special operation condition of NC.     

微型中子源反应堆热工水力安全分析

微型中子源反应堆（简称微堆）是一种典型的罐池式反应堆,采用自然对流循环冷却。为研究微堆的安全性,对其额定功率运行以及事故工况下的瞬态热工水力特性进行了模拟。针对额定功率运行工况,采用CFD软件进行瞬态热工水力三维数值模拟,同时采用RELAP5程序进行一维计算,二者计算结果相符,表明了计算结果的正确性及额定功率工况的安全性。采用RELAP5程序对反应性引入事故进行了计算,计算结果进一步印证了微堆的自稳特性和固有安全性。     

Introducing and validating a new method for coupling neutronic and thermal-hydraulic calculations

In this study, a new and innovative method is introduced for analyzing neutronic and thermal-hydraulic calculation. For this aim, VVR-S research reactor was selected, and the calculation procedure was performed for it. WIMS, CITATION and COBRA-EN codes were used for investigation. Calculation model consists of two sub-models: neutronic and thermo-hydraulic. The neutronic model uses WIMS and CITATION codes for neutronic simulation of the reactor core and calculating flux and power distribution over it. WIMS code simulates the fuel assemblies and CITATION models the core. The thermal-hydraulic model uses COBRA-EN code for performing the relative calculation. In this study, FORTRAN 90 program is used for linking two sub-models and performing the calculation. The proposed procedure is performed for VVR-S analysis and finally, the obtained results are compared with the experimental results that show good agreement with it.     

板型燃料元件反应堆瞬态热工水力分析程序的开发与验证

针对核动力系统瞬态分析的需求,建立板型燃料反应堆的热工水力数学物理模型,开发了具有自主知识产权的核动力系统瞬态热工水力分析程序SYSTRAN,并采用中国先进研究堆（CARR堆）的设计工况和国际原子能机构（IAEA）基准题的堵流瞬态数据对程序进行了验证。计算结果表明,堆芯流量分配、出口温度等关键参数与验证数据吻合良好,初步证明了本程序适用于板型燃料反应堆系统瞬态热工水力分析。      

Experimental validation of the thermal-hydraulic code SACATRI

A sub-channel analysis steady state thermal-hydraulic code (SACATRI) was developed for the Moroccan TRIGA MARK II research reactor. The main objective of the thermal-hydraulic study of the whole reactor core is to evaluate the main safety parameters of the reactor core, and to ensure that they are within the safety limits for any operating conditions. The thermal-hydraulic model used in SACATRI is based on four partial differential equations that describe the conservation of mass, energy and momentum. In order to assess the thermal-hydraulic mathematical model of SACATRI, the present paper focuses on the quantification of the physical model accuracy to judge if the code is capable to represent the thermal-hydraulic behaviour of the reactor core with sufficient accuracy. The methodology adopted is based on the comparison between responses from SACATRI computational model and experimentally measured responses performed on the IPR-R1 TRIGA research reactor. The results showed good agreement between SACATRI predictions and the experimental measurements where the discrepancies observed (simulation-experiment) are less than 6%.     

10 MW固态燃料钍基熔盐堆稳态物理-热工耦合

固态燃料钍基熔盐堆(Thorium Molten Salt Reactor-Solid Fuel,TMSR-SF1)作为第四代先进核反应堆堆型之一,继承了熔盐冷却剂和球形燃料元件的许多优点和技术基础,具有良好的经济性、设计上的固有安全性、钍铀燃料的可持续性和防核扩散性。本文以10 MW固态燃料钍基熔盐堆为模型,利用MCNP(Monte Carlo N Particle Transport Code)和ANSYS Fluent等模拟程序对其进行多物理耦合分析,同时利用C++语言编写了堆芯活性区的物理-热工耦合计算程序,实现了MCNP计算结果与Fluent程序的对接,并且通过对比耦合前后结果,分析了堆芯功率密度分布、有效增殖因子、温度分布等主要参数,为熔盐堆的设计、安全性评估和操作运行提供了参考依据。     

Reactor cavity and ALS thermal-hydraulic evaluation in the case of fuel channels ruptures at Ignalina NPP

This paper presents the work analysis of the thermal-hydraulic parameters behavior in the RBMK-1500 reactor cavity (RC) and other connected volumes in the case of fuel channels ruptures. The analysis is performed with CONTAIN code using the models of accident localization system (ALS) and reactor cavity venting system (RCVS). The RCVS capacity is assessed and expressed as a number of ruptured fuel channels at which the integrity of RC is maintained. The uncertainty analysis of pressure behavior in RC during multiple fuel channel rupture was performed. The initial and boundary conditions and the code models were selected and their influence on the results is estimated.Calculation of coolant mass and energy release to the reactor cavity in case of fuel channels rupture performed using the main circulation circuit model of Ignalina NPP, which was developed by employing state-of-the-art code RELAP5/MOD3.2 [Fletcher et al., RELAP5/MOD3 code manual user’s guidelines, Idaho National Engineering Lab., NUREG/CR-5535 (1992)]. These results were applied further as the initial data for the analysis of the thermal-hydraulic parameters behavior in the affected compartments employing CONTAIN code.