核供热堆堆芯燃料管理及优化方法的系统研究，在国内尚属首次，是堆物理设计中的一个新课题。通过优化燃料管理，对堆内燃料合理使用，减少初始铀装量，提高燃料燃耗，降低燃料费用，降低核供热成本具有很大的实际意义。本论文详细介绍了燃料管理及优化的原理和方法。本论文首先着重研究有关堆芯燃料管理的计算方法，研究了组件均匀化参数的计算，以组件计算软件包 TPFAP为工具，计算了不同类型的组件参数，用这些参数组成插值表，采用函数插值法求得全堆燃耗计算所需的截面，使在整个优化设计中，不必反复调用组件群常数计算程序。这种方法在实际运用中是成功有效的，为准确快速地进行堆芯燃料管理计算提供了很好的基础。本论文介绍的燃料管理计算程序具有计算速度快、满足一定精度要求等特点，适用于作初步设计的燃料管理计算。对粗网有限差分法与节块格林函数法（NGFM）进行了推导和比较，发现粗网有限差分法计算的有效倍增因子精度可与节块格林函数法相比较，相对误差小于0.08％，其燃耗计算值接近三维带棒的NGFM设计值。本论文提出和研究了核供热堆燃料管理优化设计的一种方法，应用哈林功率原理，将燃料组件布置与可燃毒物配置问题脱耦处理，提出了优化的物理模型。利用线性规划方法，以循环初（ BOC）等效新料富集度作为控制变量，以循环末组件平均卸料燃耗深度最大和以循环初径向功率峰因子最小为目标进行堆芯燃料组件布置优化；以可燃毒物的重量百分比为控制变量，以循环初径向功率峰因子最小为目标作可燃毒物配置优化设计。同时设计编制了一个实用的核供热堆燃料管理优化软件包，填补了核供热堆优化问题的空白。应用该软件包对实际可行的燃料管理方案进行了研究，对工程设计有重要的参考价值和应用价值。本论文应用该软件包对 200MW低温核供热堆进行了初装堆芯及换料优化计算，检验了该软件包的实用性与计算效率，研究了合理的堆芯装换料方式，使堆芯卸出的燃料能达到较高的燃耗深度，实现在给定工况下核燃料循环的最优化，以降低燃料循环的成本，提出了使堆设计更为安全经济的一种新的堆芯换料参考方案。该软件包可广泛应用于核反应堆的研究和设计，为堆物理设计提供一种有效的工具。
It is the first time in China and one of new projects in reactor physics to study the method of in-core fuel management and optimization for nu-clear heating reactors(NHR). It is practically important to effectively utilize in-core fuel, reduce initial uranium loading, improve the fuel burnup and reduce the fuel cost. This thesis studies the theory and me-thod of fuel management and optimization.Firstly, this thesis studies the methods of in-core fuel management, and the calculation of homogeneous parameters in assemblies. The fuel assem-bly software TPFAP is a basic tool, the parameters of various assemblies are calculated for interpolation tables, the cross-sections for overall core burnup calculation are calculated with a function interpolation me-thod, and it is unnecessary to repeatedly use the assembly group parame-ters programming during the optimization design. This method is practic-ally effective, and is the basis for calculating in-core fuel management fast and accurately. This thesis shows the programs for fuel management running fast and satisfactorily can meet the requirements of engineering design precision, which are effective for fuel management in preliminary design. This thesis compares a coarse mesh finite difference method with the nodal Green*s function method (NGFM), and finds the coarse mesh fi-nite difference method is effective, which method is less accurate than NGFM, the relative error between their effective multiplication factors (Keff) is less than 0.08% and the burnup calculated by the coarse mesh finite difference method is close to the NGFM design value from a three-dimension of code with control rods.This thesis improves and studies a method of fuel management and optimi-zation for nuclear heating reactors, which separates the arrangement of fuel assembly with the disposition of burnable poison using the Haling power principle, and improves the physics model of optimization. The BOC enrichment of the new fuel assemblies is used as the control variable with the objective to maximize the average assembly unloading burnup at the end of cycle(EOC) and to minimize the radial power peaking factor at the beginning of cycle(BOC) by linear programming, the assembly arrange-ment is optimized; the weight percentage of burnable pison is used as the control variable with the objective to minimize the radial power peaking factor, the disposition of burnable poison is optimized. A func-tional software for fuel management and optimization of nuclear heating reactors is designed and programmed, which fills in the blanks in the field of optimization of nuclear heating reactors. The feasible pattern of fuel management is studied with this software, and it is of important reference value and utilizing value for engineering design.This study considers optimization of initial core and reloading core of the 200MW nuclear heating reactor (NHR-200) using above software, checks the function and efficiency of this software, studies the reasonable re-loading pattern which makes the unloading fuel from the core have deeper burnup, accomplishes the nuclear fuel cycle optimization under given op-eration condition to minimize the fuel cycle cost, and improves a new reference pattern of core reloading which is much safer and more econom-ic for reactor designs. This software can be widely used in study and design of nuclear reactors, and is an effective tool for reactor physics designs.
