Article title: SP3-coupled global variance reduction method based on RMC code

文章题目：SP3耦合的全局减方差方法

DOI: 10.1007/s41365-021-00973-0

One sentence summary:

一句话概要：

A global variance reduction method was proposed to improve the efficiency of nuclear reactor design.

为了提高核反应堆设计的效率，提出了一种全局减方差方法。

http://www.nst.sinap.ac.cn/newsDetails/112/24748/en/

The Novelty (What)

创新性（主要内容）

This study developed an SP3-coupled global variance reduction (GVR) method, which brought the efficiency and accuracy of the Monte Carlo (MC) criticality calculation to a whole new level. The workflow of the SPN-based GVR involved MC global homogenization in determining global cross-sections, SP3 equation-solving to obtain the global flux distribution, and global weight windows approximation. Despite achieving a noteworthy milestone, this research aimed to enhance the GVR’s performance in the near future by involving rigorous SPN theory and an adjoint method for the SPN theory.

本文提出了一种SP3耦合的全局减方差(GVR)方法，该方法可以提高蒙特卡罗(MC)临界计算的效率和精度。 SP3耦合的全局减方差(GVR)方法的工作流程包括，通过MC全堆均匀化来获取全堆的群常数，求解SP3方程获得全堆通量分布，并使用全堆通量分布来近似全局权窗参数。 虽然该方法已经实现了较好的计算效果，未来还可以通过引入严格的SPN理论和SPN伴随算法来进一步提高它的全局减方差效果。

The Background (Why)

研究背景（主要原因）

The design and performance of a reactor rely significantly on the reactor criticality calculation, which applies the MC method most of the time. Besides enhancing the overall efficiency and accuracy, variance reduction (VR) methods are crucial in maintaining the numerical stability of MC multi-physics simulations. To fulfill the demand for a more superior reactor design, this study proposed an SP3-coupled GVR that enhanced the overall efficiency of MC criticality calculation. This development could potentially improve the reactor shielding calculations, leading to a higher-performance reactor design.

反应堆设计依赖于反应堆临界计算，而反应堆临界计算经常采用MC方法。 除了提高整体效率和精度外，减方差方法对于保证MC多物理模拟的数值稳定性至关重要。 为了满足更高效的反应器设计的要求，本研究提出了一种SP3耦合的GVR来提高MC临界计算的效率。 这一方法也可以提高反应堆屏蔽计算的效率，实现更高效的反应堆设计。

The SDG impact (Big Why)

SDG影响力（研究意义）

A nuclear reactor is built and operated based on sophisticated technology. To cope with the higher demand on its performance, various aspects such as design and safety features need to be enhanced. The GVR method proposed in this study showed great potential in pushing the limits of reactors in the future. Therefore, its achievement materialized UNSDG 9: Industry, Innovation & Infrastructure.

核反应堆是基于复杂的技术建造和运行的。 为了满足对其性能的更高要求，在设计和安全性能等方面都需要改进。 本研究中提出的GVR方法在反应堆设计领域具有很大的潜力。 因此，它的成就实现了联合国可持续发展目标9：工业、创新和基础设施。