Abstract

The analysis of the results of a depletion code is often considered a tedious and delicate task, for it requires both the processing of large volumes of information (the time-dependent composition of up to thousands of isotopes) and an extensive knowledge of nuclear reactions and associated nuclear data. From these observations, dedicated developments have been integrated to the upcoming version of the Monte Carlo depletion code VESTA 2.2 in order to implement an innovative representation of depletion problems. The aim is to provide users with an adaptable and efficient framework to ease the analysis of the results of the code and facilitate their interpretation. This effort ultimately culminates in the development of the representation of the isotopic evolution of a given system as a directed graph.

In this paper, it is shown that the Bateman equation encoded in the VESTA code indeed possesses a natural interpretation in terms of a directed cyclic graph, and it is proposed to explore some of the insight one can gain from the graph representation of a depletion problem. Starting from the new capabilities of the code, it is shown how one can build on the wealth of existing methods of graph theory in order to gain useful information about the nuclear reactions taking place in a material under irradiation. The graph representation of a depletion problem being especially simple in activation problems—for then only a limited number of nuclides and reactions are involved—the graph representation and its associated tools will be used to study the evolution of the structure materials of a simplified model of the ITER fusion reactor.

摘要

对耗竭代码结果的分析通常被认为是一项繁琐而微妙的任务，因为它既需要处理大量信息（多达数千个同位素的时间依赖性组成），又需要对核反应和核反应的广泛了解。相关的核数据。从这些观察结果来看，专门的开发已集成到即将发布的蒙特卡洛耗竭代码VESTA 2.2的版本中，以实现耗竭问题的创新表示。目的是为用户提供一个适应性强且高效的框架，以简化对代码结果的分析并促进其解释。这种努力最终以给定系统的同位素演化表示为有向图的方式达到高潮。

在本文中，表明用VESTA代码编码的Bateman方程确实对有向环图具有自然的解释，并且建议探索一些可以从耗竭问题的图表示中获得的见解。 。从代码的新功能开始，显示了如何才能在现有的图论方法的基础上获得更多信息，以获取有关材料在辐照下发生的核反应的有用信息。耗竭问题的图形表示在激活问题中特别简单-因为此时仅涉及有限数量的核素和反应-图形表示及其相关工具将用于研究简化模型的结构材料的演化ITER聚变反应堆。