次临界燃料部件典型热工实验单元模型抽取方法

次临界燃料部件是聚变-裂变混合能源系统次临界能源包层的核心部件。对燃料部件开展热工安全实验,是获取热工设计准则、开展结构设计和安全分析的基础和必要环节。本文针对包层结构原型开展模型抽取技术研究,对模块式燃料部件特殊的热工水力结构展开分析,并开展包括计算流体动力学(CFD)方法在内的相关计算确定对象参数特征,获取典型热工实验单元的基本结构和参数。     

混合堆、聚变堆包层热工水力与中子学综合分析模拟及FEB混合堆包层综合分析

为了混合堆及聚变堆包层分析的需要，开发了ＢＩＴＨ程序，以对包层的热工水力学及中子学进行综合分析。简述球床的热工水力特征及其数学物理模型，介绍编制的包层热工水力分析程序ＴＨＰＢＨＲ，对ＢＩＳＯＮ１．５全面改造，考虑了共振自屏效应，并与热工水力计算相耦合，并更换ＢＩＳＯＮ１．５自带数据库，修改燃耗计算方法，以适应放射性废物处理、辐照损伤等计算需要。还对ＦＥＢ混合堆外包层用ＢＩＴＨ程序进行了分析。     

ITER中国液态锂铅实验包层模块结构热应力数值模拟

使用有限元程序对中国向国际热核实验堆ITER实验包层工作组提交的双功能锂铅实验包层模块(DFLL-TBM)的两种结构设计方案即双冷LiPb包层DLL和单冷准静态LiPb包层SLL进行热应力数值模拟,在包层结构设计、热工水力学设计和中子学计算基础上,给出包层结构温度场和应力场分布,依据ITER高温结构设计标准,进一步对包层高温部件进行力学性能分析.根据这些模拟结果,分析两种结构基本设计方案的合理性和可行性,并作为进一步优化分析的基础.     

基于RELAP5的双功能液态锂铅实验包层模块安全分析

利用嵌入了液态锂铅（LiPb）的热工水力子模块的系统程序RELAP5/MOD3,对双功能液态锂铅（DFLL）实验包层模块（TBM）的安全特性进行评价。对DFLL-TBM及其辅助冷却系统的稳态运行工况、预期运行事件和相关事故工况进行了建模、计算和分析。计算结果表明,稳态运行时第一壁（FW）结构材料表面最高温度低于允许值550 ℃。事故工况下氦气泄漏引起的ITER真空室（VV）、窗口设备室（port cell）以及托卡马克冷却水系统大厅拱顶（TCWS vault）的增压均低于ITER要求的限值0.2 MPa。实验包层钢结构不会熔化且可通过辐射换热有效地导出衰变余热。DFLL-TBM的设计可满足ITER对其热工水力安全方面的要求。     

He冷却LLi氚增殖包层的热工水力初步设计

完成了托卡马克工程试验混合堆ＴＥＴＢ－Ⅲ Ｈｅ冷液态金属Ｌｉ（ＬＬｉ）氚增殖包层的初步热工水力设计，探讨了包层中载氚的两种可能方式，同时，用程序完成了对第一壁和包层的温度场计算及热工水力设计参数的初步优化。分析结果表明，尽管Ｈｅ气的导热性和密度都比液态金属冷却剂低得多，但仍有可能使堆芯在２．０ＭＰａ的低压下运行，并且包层的热工水力设计参数满足设计要求。     

聚变增殖堆液态金属Li自冷包层的热工水力分析

完成了托卡马克商用混合堆 TCB(Tokamak Commercial Breeder)Li 自冷包层设计的热工水力分析,讨论了热工水力设计中的一些关键问题。用两维有限元热传导程序 AYER 计算了 TCB 包层的温度分布,用液态金属 MHD(Magnetohydraudynamic)压降公式计算了包层的压降。同时,还分析了包层冷却剂丧失事故 LOCA 的瞬态热工过程。分析表明,正常工况下,包层结构材料最高温度,结构材料与冷却剂界面最高温度,以及包层总压降都满足堆设计要求。在 LOCA 工况下,如果停堆后1小时内包层中的燃料球能够借助重力卸出包层,第一壁和包层是安全的,并且不会受到损伤。     

高温氦气实验回路氢气主冷却回路的概念设计

依据聚变堆包层热工水力实验段的设计要求,并借鉴国内外氦气实验回路的设计和运行经验,对国际热核聚变实验堆(ITER)氦冷固态增殖剂实验包层模块(HCSB-TBM)高温氦气实验主回路进行了概念设计.主要给出了氦气实验主回路(HTHEL)的主要设计参数、回路系统构成及主要设备特点,并对主管道设计进行了应力校核.     

聚变实验堆ITER实验包层瞬态热工安全分析

在中国向ITER(International Thermonuclear Experiment Reactor)实验包层工作组提交的双功能锂铅实验包层模块(DFLL-TBM)设计分析的基础上,通过对DFLL-TBM系统相关的瞬态事故如真空室内部冷却剂泄漏、TBM(实验包层模块)内部冷却剂泄漏以及真空室外部冷却剂泄漏事故进行计算分析,评价DFLL-TBM对ITER在热工方面对安全的影响.结果表明:当发生瞬态事故时,DFLL-TBM有能力通过热辐射将余热排出,且包层结构不会熔化.DFLL-TBM可满足ITER在热工方面对安全的要求.     

基于RELAP5的螺旋管蒸汽发生器热工水力程序研发与验证

由于较高的换热效率和紧凑的结构设计,螺旋管式直流蒸汽发生器（HCOTSG）在多种模块化小型堆的设计中得到了广泛应用。RELAP5作为广泛应用于反应堆热工水力特性分析的大型系统程序之一,采用的热工水力关系式仅针对直管模型开发,不适用于HCOTSG一次侧和二次侧。本文选用螺旋管及横掠管束的热工水力模型,基于RELAP5程序开发了HCOTSG模块。采用实验数据及程序对比等方式对螺旋管模块的流动和换热模型进行了单独验证,利用开发的RELAP5-HCOTSG程序针对国际革新安全反应堆（IRIS）的蒸汽发生器设计进行了整体的热工水力模拟,与原始RELAP5的计算相比,RELAP5-HCOTSG程序计算得到的热工水力参数与设计值符合良好,确认了本文开发的程序模块在HCOTSG热工水力分析中的适用性。     

聚变驱动次临界堆双冷嬗变包层热工水力学参数设计与分析

聚变驱动次临界堆双冷嬗变包层是一个以氦气和液态金属LiPb为冷却剂,以嬗变核废料为主要目的的多功能包层。依据功率平衡模型对不同工况优化的基础上,对该包层热工系统参数进行了设计分析。采用三维商用计算流体力学程序对第一壁和高功率密度区中液态LiPb的流场进行数值模拟计算,给出了优化的典型热工水力参数。     

New genetic algorithms (GA) to optimize PWR reactors: Part I: Loading pattern and burnable poison placement optimization techniques for PWRs

The objective of this study was to develop a unique scientific methodology as well as a practical tool for designing the loading pattern (LP) and burnable poison (BP) pattern for a given Pressurized Water Reactor (PWR) core. Because of the large number of possible combinations for the fuel assembly (FA) loading in the core, the design of the core configuration is a complex optimization problem. It requires finding an optimal FA arrangement and corresponding BP placement design that will achieve maximum cycle length while satisfying the safety constraints. To solve this optimization problem, a core reload optimization package, GARCO (Genetic Algorithm Reactor Code Optimization) code is developed. This code is applicable for all types of PWR cores having different geometries and designs with an unlimited number of FA types in the inventory. GARCO has three modes: the user can optimize the core configuration (LP pattern) with or without BPs in the first mode; the second mode is the optimization of BP placement in the core and the last mode is the user can optimize LP and BP placements simultaneously in mode 3. In this study, the first mode finds the optimal LPs using the Haling Power Depletion Method (HPD) for placing BPs in the core. The second mode, which depletes the core accurately, places BPs in the selected optimum LP pattern. This methodology is applied only to the TMI-1 PWR. However, the improved Mode 1 GA option was applied to both the VVER-1000 and the TMI-1 to demonstrate and verify the advantages of the new enhancements in optimizing the LP pattern only. The “Moby-Dick” code is used as reactor physics code for VVER-1000 analysis in this research. The SIMULATE-3 code, which is an advanced two-group nodal code, is used to analyze the TMI-1. The libraries of the BP designs used in SIMULATE-3 in this study were produced by Yilmaz (2005) [Yilmaz, S., 2005. Multilevel optimization of burnable poison utilization for advanced PWR fuel management. Ph.D. Thesis in Nuclear Engineering. the Pennsylvania State University].     

基于遗传算法的闭式非能动安全壳热量导出系统排热能力优化

以闭式非能动安全壳热量导出系统（PCCS）概念方案为研究对象，基于一维两相均相流模型建立了评价该系统排热能力的物理模型，并开发了相应的计算程序；开发了基于遗传算法的优化设计程序；利用所开发的优化设计程序，对闭式PCCS概念方案的排热能力进行优化，给出了系统几何参数和运行参数的优化方向。结果表明：在所研究参数范围内，适当增加内部和外部换热器传热管径可增加系统排热能力；最佳外/内部换热器传热管数比为1.58。     

遗传算法在压水堆平衡循环优化中的应用研究

建立了遗传算法用于核电站平衡循环优化的数学模型 ;提出了该模型的遗传编码和遗传操作 ,完成相关程序编制 ;并和NNGFM堆芯物理计算程序构成一个完整的堆芯燃料管理程序。为了检验优化效果 ,以大亚湾核电站第 5炉参数作为参考方案 ,在无初值的情况下 ,针对不同的目标函数进行平衡循环优化。结果表明 ,循环长度最大化能延长 1 0EFPD左右 ,功率峰因子最小化使得功率峰因子从1 3 6降低到 1 2 9。     

含可燃毒物的压水堆堆芯装料优化

含可燃毒物的压水堆堆芯装料优化是燃料管理优化研究中的难点。应用通常的优化算法效率低、全局性差,特征统计算法更适合求解该优化问题。本研究克服了原特征统计算法装料优化将组件布置(LP)优化和新组件可燃毒物配置(BP)优化脱耦处理的缺陷,对LP和BP同时进行优化,结合堆芯分析程序CYCLE2D,成功地研制了压水堆LP和BP耦合优化程序CSALPBP。用该程序对大亚湾2号机组第10循环进行了堆芯装料优化计算。结果表明：CSALPBP程序具有很高的搜索效率和很好的全局性。     

Application of the Distributed Genetic Algorithm for In-Core Fuel Optimization Problems under Parallel Computational Environment

The distributed genetic algorithm (DGA) is applied for loading pattern optimization problems of the pressurized water reactors. A basic concept of DGA follows that of the conventional genetic algorithm (GA). However, DGA equally distributes candidates of solutions (i.e. loading patterns) to several independent “islands” and evolves them in each island. Communications between islands, i.e. migrations of some candidates between islands are performed with a certain period. Since candidates of solutions independently evolve in each island while accepting different genes of migrants, premature convergence in the conventional GA can be prevented.

Because many candidate loading patterns should be evaluated in GA or DGA, the parallelization is efficient to reduce turn around time. Parallel efficiency of DGA was measured using our optimization code and good efficiency was attained even in a heterogeneous cluster environment due to dynamic distribution of the calculation load. The optimization code is based on the client/server architecture with the TCP/IP native socket and a client (optimization) module and calculation server modules communicate the objects of loading patterns each other.

Throughout the sensitivity study on optimization parameters of DGA, a suitable set of the parameters for a test problem was identified. Finally, optimization capability of DGA and the conventional GA was compared in the test problem and DGA provided better optimization results than the conventional GA.     

基于遗传算法的中子屏蔽材料组分优化研究

基于快速非支配排序遗传算法NSGA-II,开展了多目标屏蔽优化设计研究,建立了中子复合屏蔽材料组分的自动优化设计程序。以屏蔽剂量和材料密度最小化为目标,以聚乙烯、铅、硼、锂、铁、铝等材料均匀混合组成30 cm厚平板屏蔽结构为例,验证了优化算法程序的有效性。将基于遗传算法的屏蔽优化方法与设计人员的经验相结合,可更高效地实现多目标屏蔽优化设计。     

New genetic algorithms (GA) to optimize PWR reactors: Part III: The Haling power depletion method for in-core fuel management analysis

The Haling Power Distribution (HPD) has been applied in a unique process to greatly accelerate the in-core fuel management optimization calculations. These calculations involve; the arrangement of fuel assemblies (FAs) and the placement of Burnable Poisons (BPs) in the fresh FAs. The HPD deals only with the arrangement of FAs. The purpose of this paper is to describe past uses of the HPD, provide an example selected from many similar calculations to explain why and how it can be used, and also to show its effectiveness as a filter in the GARCO GA code. The GARCO (Genetic Algorithm Reactor Core Optimization) is an innovative GA code that was developed by modifying the classical representation of the genotype and GA operators. A reactor physics code evaluates the LPs in the population using the HPD Method, which rapidly depletes the core in a single depletion step with a constant power distribution. The HPD is used basically in GARCO as a filter to eliminate invalid LPs created by the genetic operators, to choose a reference LP for BP optimization, and to create an initial population for simultaneous optimization of the LP and BP placement into the core. The accurate depletion calculation of the LP with BPs is done with the coupled lattice and reactor physics CASMO-4/SIMULATE3 package. However, the fact that these codes validate safety of the core with the added BP placement design also validates the use of the HPD method. The calculations are applied to the TMI-1 core as an example PWR providing concrete results.     

An Interval Bound Algorithm of optimizing reactor core loading pattern by using reactivity interval schema

In order to optimize the core loading pattern in Nuclear Power Plants, the paper presents a new optimization method – Interval Bound Algorithm (IBA). Similar to the typical population based algorithms, e.g. genetic algorithm, IBA maintains a population of solutions and evolves them during the optimization process. IBA acquires the solution by statistical learning and sampling the control variable intervals of the population in each iteration. The control variables are the transforms of the reactivity of fuel assemblies or the worth of burnable poisons, which are the crucial heuristic information for loading pattern optimization problems. IBA can deal with the relationship between the dependent variables by defining the control variables. Based on the IBA algorithm, a parallel Loading Pattern Optimization code, named IBALPO, has been developed. To deal with multiple objectives and constraints, the Dynamic Discontinuous Weight Factors (DDWF) for the fitness function have been used in IBALPO. Finally, the code system has been used to solve a realistic reloading problem and a better pattern has been obtained compared with the ones searched by engineers and genetic algorithm, thus the performance of the code is proved.     

超临界水冷堆双排燃料组件子通道分析

研究基于Cobra-IV程序,开发了适用于超临界水冷堆燃料组件分析的子通道程序.针对超临界水冷堆慢谱双排组件,进行了稳态计算,获取了相关组件热工水力参数.在此基础上,针对单一通道进行了瞬态计算,分析了燃料棒线功率变化和冷却剂流量变化条件下,超临界水冷堆燃料组件的流动和传热的动态响应,为超临界水冷堆组件的优化设计提供了参考.     

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。