In this study, preliminary neutronic calculations were performed in order to provide a basic design of a prismatic-core advanced high temperature reactor (PAHTR) that adapts a mixture of lithium fluoride and beryllium fluoride (Li₂BeF₄, known as FLiBe) as a coolant. This work investigates the effectiveness of utilizing an integral fuel burnable absorber (IFBA) as an additional coating layer for the outer surface of the fuel kernel of the tri-structural isotropic (TRISO) fuel particle. A parametric study was performed to attain a targeted cycle length of 60 months and a fuel burnup greater than 90 MWd/kgU for fuel unit cell, and 70 MWd/kgU and 45 MWd/kgU for 2D and 3D full reactor core, respectively, with a uranium enrichment of 19.75 w/o to support non-proliferation goals. This paper discusses the idea of applying homogeneous distribution of IFBA as an additional coating layer with different thicknesses through the reactor core and perform preliminary neutronics analysis on the reactivity control mechanism for both two- and three-dimensionals core. The Monte Carlo Serpent code has been utilized to estimate the core reactivity balance using the cycle length by reducing the burnup swing between the beginning of cycle (BOC) and end of cycle (EOC). This can be done by adopting the innovative idea of covering the outer surface of the fuel kernel with a thin coating layer of IFBA. This technique is utilized in the 3D evaluation of the PAHTR reactor. Additionally, the neutron spectrum, peaking factor (axial and radial), and multiplication factor for the 3D PAHTR reactor core at the BOC, middle of the cycle (MOC), and EOC were compared by taking into account the double heterogeneity nature of the TRISO fuel particles embedded in the graphite matrix.

在这项研究中，进行了初步的中子计算，以提供一种棱柱形堆芯先进高温反应堆 (PAHTR) 的基本设计，该反应堆采用氟化锂和氟化铍 (Li ₂ BeF ₄，称为 FLiBe）作为冷却剂。这项工作研究了利用整体燃料可燃吸收剂 (IFBA) 作为三结构各向同性 (TRISO) 燃料颗粒燃料核外表面的附加涂层的有效性。进行了一项参数研究，以实现 60 个月的目标循环长度和大于 90 MWd/kgU 的燃料单电池的燃料燃耗，以及 70 MWd/kgU 和 45 MWd/kgU 的 2D 和 3D 全反应堆堆芯，以及铀浓缩 19.75 w/o 以支持不扩散目标。本文讨论了应用均匀分布的 IFBA 作为通过反应堆堆芯的不同厚度的附加涂层的想法，并对二维​​和三维堆芯的反应性控制机制进行了初步中子学分析。Monte Carlo Serpent 代码已被用于通过减少循环开始 (BOC) 和循环结束 (EOC) 之间的燃耗摆动，使用循环长度来估计核心反应性平衡。这可以通过采用用 IFBA 薄涂层覆盖燃料内核外表面的创新理念来实现。该技术用于 PAHTR 反应器的 3D 评估。此外，考虑到 TRISO 的双重非均质性，对 BOC、循环中间 (MOC) 和 EOC 的 3D PAHTR 反应堆堆芯的中子谱、峰值因子（轴向和径向）和倍增因子进行了比较嵌入石墨基体中的燃料颗粒。