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.

我们专注于第三代和第四代反应堆运行模拟、燃料管理和安全分析所需的全堆芯反应堆物理代码。中子扩散理论目前用于此目的，但参考计算需要更准确地表示输运现象。基于与 MOC 和计算机集群发展相关的最新进展，我们现在可以提出实施一系列严格的全核解决方案技术，该技术依赖于离散坐标方法（对于规则几何形状）和 MOC（对于非结构化几何形状）。我们建议开发的 MOC 是基于以下内容的原创贡献： 1.线性源。假设散射源和裂变源沿着每个轨道段交叉点线性变化 域。使用抛物线阶菱形差分方案来获得每个中的通量矩 体积。大多数当前的实现都是基于平坦源近似和阶跃特性 差异化。 2.散射各向异性。通过 MOC 解决方案，我们建议实施变阶 Legendre 散射各向异性的展开模型。 3.合成加速。 DRAGON4 代码中已经实现的 MOC 使用仅限于平面源和各向同性散射的二阶代数塌陷 (AC) 方法进行加速。我们建议用一阶 AC 方法代替二阶 AC 方法，并将其散射表示推广到更高阶。 4.并行性。我们建议使用 Fortran-2008 ISO 标准的名为“coarray”的功能来实现 适用于 MOC 和 AC 方法的大规模并行解决方案技术。龙4 MOC 的实施目前尚未并行。使用 Unified Portable C (UPC) 是一种替代方法 用 C 语言编写的算法的大规模并行求解技术。