Nuclear reactor full-core deterministic computational schemes in transport theory

输运理论中核反应堆全核确定性计算方案

• 批准号: 107847-2011
• 负责人: Hébert, Alain
• 金额: $ 1.97万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569148
• 关键词: Nuclear; reactor; full; core; deterministic

We are focusing on full-core reactor physics codes required for simulation of operation, fuel management and safety analyses of third- and fourth-generation reactors. Neutron diffusion theory is currently used for this purpose, but reference calculations require a more accurate representation of transport phenomena. Based on recent advances related to the MOC and to the evolution of computer clusters, we can now propose the implementation of a family of rigorous full-core solution technique relying on the discrete ordinates method (for regular geometries) and on the MOC (for unstructured geometries). The MOC we propose to develop is an original contribution based on: 1. linear sources. Scattering and fission sources are assumed to vary linearly along each track segment crossing the domain. A parabolic order diamond differencing scheme is used to obtain the flux moments in each volume. Most current implementations are based on flat sources approximation and step-characteristic differencing. 2. scattering anisotropy. With the MOC solution, we propose to implement a variable-order Legendre expansion model for scattering anisotropy. 3. synthetic acceleration. The MOC already implemented in DRAGON4 code is accelerated using a second-order algebraic collapsing (AC) method limited to flat sources and isotropic scattering. We propose to replace the second-order AC method with a first-order AC method and to generalize its scattering representation to higher orders. 4. parallelism. We propose to use a capability of Fortran-2008 ISO standard named "coarray" to implement a massively-parallel solution technique adapted to the MOC and to the AC method. The DRAGON4 implementation of the MOC is currently not parallelized. Using the Unified Portable C (UPC) is an alternative massively-parallel solution technique for algorithms written in C language.

我们专注于模拟第三代和第四代反应堆的操作，燃料管理和安全分析所需的全核反应堆物理代码。中子扩散理论目前用于此目的，但是参考计算需要更准确地表示转运现象。基于与MOC和计算机簇的演变有关的最新进展，我们现在可以提出依赖于离散坐标方法（常规几何）和MOC（对于非结构化的几何形状）的严格全核解决方案技术的实施。我们建议开发的MOC是基于： 1。线性来源。假定散射和裂变源沿每个轨道段交叉线性变化 域。抛物线级钻石差异方案用于获得每种磁通矩 体积。大多数当前的实现都是基于平坦的近似和步骤特征的基础 差异。 2。散射各向异性。使用MOC解决方案，我们建议实现可变订单的Legendre 散射各向异性的扩展模型。 3。合成加速度。使用二阶代数崩溃（AC）方法限于扁平源和各向同性散射的二阶代数崩溃（AC）方法，已在Dragon4代码中实现的MOC加速。我们建议用一阶AC方法替换二阶AC方法，并将其散射表示形式推广到更高阶。 4。平行性。我们建议使用名为“ coarray”的Fortran-2008 ISO标准的功能来实现 大规模并行的溶液技术适用于MOC和AC方法。龙4 MOC的实现目前不同行。使用统一的便携式C（UPC）是替代方案 用C语言编写的算法的大规模并行解决方案技术。