Advanced thermochemical modelling for recycling spent Canadian nuclear fuels

这项申请建议开发一种新的热力学核燃料回收模式，这将扩大加拿大在乏核燃料回收领域的知识和专长。结果可以用来定义和集中未来的努力，以制定一个可行的回收计划，与国际协议和加拿大未来的能源需求相兼容。加拿大核废物管理组织建议采用适应性分阶段管理办法，将一次通过的乏燃料最终储存在一个孤立的深层地质储存库中。这种方法是浪费的，因为乏燃料含有可从裂变产物中提取并重新引入核燃料循环的未使用的可育同位素和裂变同位素。这项赠款申请中概述的研究的目的是促进加拿大在回收核燃料领域的知识基础和专门知识。为了实现这一目标，提出了一种经过验证的热力学核燃料回收模型。将建立一个热力学模型，能够预测部分燃烧的燃料在后处理时的相平衡。申请人之前开发的低浓缩铀-裂变产物燃料模型将成为这一新的核燃料回收模型的基础。虽然目前的模型已经成功地使用并提供了坚实的基础，但还需要大量的努力来改进该模型，以准确地考虑燃料回收中遇到的水和气态化学。拟议的工作将包括将这些化合物和相添加到模型中，然后用离散的热焓测量进行证实。这一模型的发展是有益的，因为它允许建模者从理论上预测燃料材料的行为，适用于广泛的化学加工技术。使用该模型，可以确定最可行的化学后处理技术，而不需要昂贵和危险的实验。然后，最有希望的技术可以通过少量的物理测试进行实验研究。作为研究的一部分，开发了一种辅助实验工作的钼基氧传感器。

This application proposes the development of a new thermodynamic nuclear fuel recycling model that will expand Canada's knowledge and expertise in the area of spent nuclear fuel recycling. The results can be used to define and focus future efforts to develop a viable recycling program compatible with international agreements and Canada's future energy needs. The Nuclear Waste Management Organization of Canada recommends the use of the Adaptive Phased Management approach whereby the single-pass spent fuel is stored ultimately in an isolated Deep Geological Repository. This approach is wasteful as the spent fuel contains unused fertile and fissile isotopes that could be extracted from the fission products and re-introduced into the nuclear fuel cycle. The aim of the research outlined in this grant application is to advance Canada's knowledge base and expertise in the area of recycling nuclear fuel. To achieve this objective, the development of a validated thermodynamic nuclear fuel recycling model is proposed. A thermodynamic model capable of predicting the phase equilibrium of the partially burned fuel as it is reprocessed would be created. The Low Enriched UO2-fission product fuel model, previously developed by the applicant, will be the basis of this new nuclear fuel recycling model. While the current model has been used successfully and provides a solid foundation, extensive effort is required to enhance the model to account accurately for aqueous and gaseous chemistry encountered in fuel recycling. The proposed work will involve the addition of these compounds and phases to the model, followed by corroboration with discrete enthalpy measurements. The development of this model is beneficial as it allows the modellers to predict theoretically the behaviour of the fuel material for a wide spectrum of chemical processing techniques. Using the model, the most viable technique for chemical reprocessing can be determined without costly and hazardous experimentation. The most promising technique then could be investigated experimentally with a small number of physical tests. As part of the research, the development of a Mo-based oxygen sensor to assist experimental work is included.