An improved depletion coupling scheme is presented, employing reduced-order transport solutions at substeps between high-fidelity solutions. The purpose of the reduced-order solver is to quickly approximate how the one-group flux would change within the depletion interval. This method builds off existing substep methods, where smaller depletion intervals are used to better approximate reaction rates and material compositions. The proposed scheme relies on the use of reduced-order transport simulations at the substeps, allowing the new compositions to influence the scalar neutron flux in other materials, approaching a time-continuous model of reaction rates. The hybrid approach is achieved by coupling a Monte Carlo code to a perturbation-theory-based reduced-order solver in a custom framework. The results demonstrate that the reduced-order solutions provide increased stability compared to the standard predictor time integration scheme, as well as higher order methods. This stability translates to increased accuracy for modeling problems where stability is an issue.

提出了一种改进的耗尽耦合方案，该方案在高保真度解决方案之间的子步骤中采用降阶传输解。降阶求解器的目的是快速估算一组磁通在耗尽间隔内的变化情况。该方法建立在现有的子步骤方法的基础之上，在该方法中，使用较小的消耗间隔可以更好地估算反应速率和材料组成。拟议的方案依赖于在子步骤中使用降阶传输模拟，从而使新的成分能够影响其他材料中的标量中子通量，从而接近反应速率的时间连续模型。通过在定制框架中将蒙特卡洛代码耦合到基于扰动理论的降阶求解器来实现混合方法。结果表明，与标准预测器时间积分方案以及高阶方法相比，降阶解提供了更高的稳定性。这种稳定性可以提高对稳定性有问题的建模问题的准确性。