To accelerate depletion calculations, it is common to only consider a selection of isotopes. Simulating only a limited number of nuclides leads inevitably to some bias on the outputs of the depletion simulation. Most methods used are either implicit or dedicated to specific cases. This paper presents a new method, based on physics consideration and an explicit algorithm, that automatically selects isotopes and reactions for a depletion calculation. This method uses the creation and simplification of a nucleus tree gathering and linking together all nuclides that can possibly be created during the depletion process. This is performed by recursively adding nuclides possibly created from nuclides previously in the tree through decay or nuclear reaction. After the creation of the tree, it can be simplified by automatically cutting nuclides and reaction out through 3 processes: half-life threshold, cross-section threshold and reaction type cut. Using these simplification processes, the presented method leads to important calculation cost reduction (up to 40%) with effect on outputs lower than 3 times their stochastic standard deviation.

为了加速消耗计算，通常只考虑同位素的选择。仅模拟有限数量的核素不可避免地导致耗尽模拟输出的某些偏差。使用的大多数方法是隐式的或专用于特定情况的。本文提出了一种基于物理考虑和显式算法的新方法，该方法可自动选择同位素和反应进行耗竭计算。此方法使用了创建和简化的核树，该树收集并链接了可能在耗尽过程中创建的所有核素。这是通过递归地添加可能由先前通过衰变或核反应在树中形成的核素而产生的核素来执行的。创建树后，通过自动切割核素并通过以下三个过程进行反应可以简化此过程：半衰期阈值，横截面阈值和反应类型切割。使用这些简化过程，所提出的方法可以显着降低计算成本（最多40％），并且对输出的影响低于其随机标准差的3倍。