Abstract

The deployment of molten salt reactors requires validation of the computational tools used to support the licensing process. The Molten Salt Reactor Experiment (MSRE), built and operated in the 1960s, offers a unique inventory of experimental data for reactor physics benchmarks. The first benchmark based on the MSRE appeared in “The 2019 Edition of the IRPhEP [International Reactor Physics Experiment Evaluation Project] Handbook.” The benchmark refers to the first criticality experiment at zero power, stationary salt, and uniform temperature with ²³⁵U fuel. Simulations carried out for the developed benchmark model with the Monte Carlo code Serpent and ENDF/B-VII.1 cross-section library found that the calculated neutron multiplication is 1.02132 (±3 pcm) and that the combined bias of the model and experimental uncertainty is below 500 pcm. Such discrepancy between the experimental and calculated k_eff is not uncommon in benchmarks for graphite-moderated systems. The model created through this effort paves the way to additional benchmarks targeting reactor physics quantities of interest beyond multiplication factor.

摘要

熔盐反应堆的部署需要验证用于支持许可过程的计算工具。熔盐反应堆实验 (MSRE) 于 1960 年代建造和运行，为反应堆物理基准提供了独特的实验数据清单。第一个基于 MSRE 的基准出现在“2019 年版的 IRPhEP [国际反应堆物理实验评估项目]手册”中。基准是指在零功率、固定盐和均匀温度下的第一个临界实验，温度为²³⁵燃料。使用 Monte Carlo 代码 Serpent 和 ENDF/B-VII.1 截面库对开发的基准模型进行的模拟发现，计算出的中子倍增为 1.02132 (±3 pcm)，并且模型的组合偏差和实验不确定性低于 500 pcm。实验和计算 k _eff之间的这种差异在石墨慢化系统的基准测试中并不少见。通过这项工作创建的模型为针对除倍增因子之外感兴趣的反应堆物理量的其他基准铺平了道路。