Abstract

This paper demonstrates a multiphysics solver for pebble-bed reactors, in particular, for Berkeley’s pebble-bed -fluoride-salt-cooled high-temperature reactor (PB-FHR) (Mark I design). The FHR is a class of advanced nuclear reactors that combines the robust coated particle fuel form from high-temperature gas-cooled reactors, the direct reactor auxiliary cooling system passive decay removal of liquid-metal fast reactors, and the transparent, high-volumetric heat capacitance liquid-fluoride salt working fluids (e.g., FLiBe) from molten salt reactors. This fuel and coolant combination enables FHRs to operate in a high-temperature, low-pressure design space that has beneficial safety and economic implications. The PB-FHR relies on a pebble-bed approach, and pebble-bed reactors are, in a sense, the poster child for multiscale analysis.

Relying heavily on the MultiApp capability of the Multiphysics Object-Oriented Simulation Environment (MOOSE), we have developed Cardinal, a new platform for lower-length-scale simulation of pebble-bed cores. The lower-length-scale simulator comprises three physics: neutronics (OpenMC), thermal fluids (Nek5000/NekRS), and fuel performance (BISON). Cardinal tightly couples all three physics and leverages advances in MOOSE, such as the MultiApp system and the concept of MOOSE-wrapped applications. Moreover, Cardinal can utilize graphics processing units for accelerating solutions. In this paper, we discuss the development of Cardinal and the verification and validation and demonstration simulations.

摘要

本文演示了用于球床反应器的多物理场求解器，特别是用于伯克利的球床-氟化物-盐冷却高温反应器 (PB-FHR)（Mark I 设计）。FHR 是一类先进的核反应堆，它结合了来自高温气冷反应堆的坚固的涂层颗粒燃料形式、液态金属快堆的直接反应堆辅助冷却系统被动衰变去除以及透明的高体积热量来自熔盐反应器的电容液态氟化物盐工作流体（例如 FLiBe）。这种燃料和冷却剂的组合使 FHR 能够在具有有益安全和经济意义的高温、低压设计空间中运行。PB-FHR 依赖于球床方法，从某种意义上说，球床反应器是多尺度分析的典型代表。

严重依赖多物理场面向对象仿真环境 (MOOSE) 的 MultiApp 功能，我们开发了 Cardinal，这是一种用于球床岩心低长度尺度仿真的新平台。较低长度尺度的模拟器包括三个物理：中子学 (OpenMC)、热流体 (Nek5000/NekRS) 和燃料性能 (BISON)。Cardinal 将所有三个物理场紧密结合在一起，并利用 MOOSE 中的进步，例如 MultiApp 系统和 MOOSE 包装应用程序的概念。此外，Cardinal 可以利用图形处理单元来加速解决方案。在本文中，我们讨论了 Cardinal 的开发以及验证和验证以及演示模拟。