Abstract Electrochemical reprocessing (also commonly known as pyroprocessing) of used nuclear fuel is an alternative to aqueous reprocessing that confers a number of advantages, including the ability to process more recently discharged fuel, smaller resultant waste volumes, and the lack of isolation of plutonium in the product stream. While electrochemical reprocessing systems have seen a significant research and development effort, nuclear safeguards and the security of these systems remain underdeveloped, particularly given the significant differences in operating environment and process flow sheet compared with established aqueous methods. In this paper we present an overview of the current state of the art for several of the most promising candidate techniques for material accountancy and process monitoring measurements for electrochemical separations facilities for used nuclear fuel, specifically passive radiation signatures (gamma spectroscopy, neutron spectroscopy, alpha spectrometry, calorimetry, and microcalorimetry), active radiation signatures (X-ray interrogation and its derivatives, high-resolution X-ray, k-edge densitometry, and hybrid k-edge densitometry; laser-induced breakdown spectroscopy; active neutron interrogation and neutron coincidence counting; inductively coupled plasma mass spectrometry; and optical measurements such as ultraviolet visible spectroscopy, near-infrared spectroscopy, and Raman spectroscopy), and control and process state variable monitoring (cyclic voltammetry and bulk measurements such as level and density, load cell forces, and off-gas monitors). This assessment includes an evaluation of each measurement’s respective modality (i.e., whether the measurement relates to elemental, isotopic, or other properties), published best estimates of measurement precision, measurement latency, and an overall evaluation of each technique’s level of technical maturity. Additionally, this study assesses the most likely locations within the pyroprocessing flow sheet where measurements may be deployed, the physical information required to properly capture the behavior of such measurements, and potential modeling strategies for such measurements. This latter component thus serves to inform future development of process monitoring models in existing and proposed electrochemical separations simulation models.

中文翻译：

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电化学分离设施材料计量测量的候选技术回顾

摘要 用过的核燃料的电化学后处理（也通常称为高温处理）是水性后处理的替代方法，它具有许多优点，包括处理最近排放的燃料的能力、产生的废物量更小，以及缺乏对钚的分离。产品流。虽然电化学后处理系统已经进行了大量的研究和开发工作，但这些系统的核安全保障和安全性仍然不完善，特别是考虑到与已建立的水处理方法相比，操作环境和工艺流程存在显着差异。以及控制和过程状态变量监测（循环伏安法和体积测量，例如液位和密度、称重传感器力和废气监测器）。该评估包括对每个测量各自模式的评估（即，测量是否与元素、同位素或其他特性有关）、已发布的测量精度、测量延迟的最佳估计以及对每种技术的技术成熟度水平的总体评估。此外，这项研究还评估了高温处理流程中最有可能部署测量的位置、正确捕获此类测量行为所需的物理信息以及此类测量的潜在建模策略。