Investigation of the safe removal of fuel debris: multi-physics simulation

燃料碎片安全清除的研究：多物理场模拟

• 批准号: EP/P013198/1
• 负责人: Christopher Pain
• 金额: $ 64.22万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FP013198%2F1
• 关键词: Investigation; safe; removal; fuel; debris

Modern computational codes can be very useful in assessing the behaviour of nuclear power facilities and ensuring that they present minimal hazard to; the public, facility workers and the environment when they enter unintended operating scenarios. This proposal will develop such methods, and will establish a simulation tool that is; accurate, robust, efficient and validated, and able to determine the levels of confidence that we can place on the models. It will be used for predicting possible consequences of reactor decommissioning and clean up following a severe nuclear accident. It also seeks to help establish advanced computational methods to investigate aspects of reactor behaviour during severe accidents. The technology proposed will help provide accuracy that is beyond what is currently possible, and will allow the physics to be explored that cannot be reproduced through experiment. The work proposed here seeks to achieve this by developing a basis for the verification and validation of computational tools against benchmark cases that will then be used to simulate more complex/realistic scenarios. The project will combine the expertise from the UK and Japan, both within academia and industry.This project will investigate two aspects of decommissioning of its debris from severe nuclear accidents as well as the prediction of the evolution of core's materials during an accident. The evolution of the core material is important for decommissioning as it helps determine the final state of the internal structures within the reactor. Due to the condition of one of the Fukushima's stricken reactors, dry decommissioning, where the core is not flooded with water, may be necessary, and this novel method of fuel removal will be investigated here. An issue with dry removal is that it introduces the problem associated with radioactive dust being released into the atmosphere. Dust emissions will occur when the core is opened and parts of its debris are cut and removed. These particles will disperse and move within the air and so will present dangers to both site personnel and the immediate environment. To mitigate the severity of dust propagation fine mist sprays will be deployed within the core's surroundings to capture and remove dust particles from the air. The suitability of such an approach (and whether sufficient shielding to the environment is maintained) will be determined here where advanced modelling methods will be developed to simulate dust dispersion within the reactor and the particles' interaction with the water droplets. Using fine sprays may also overcome a second issue regarding dry removal by providing sufficient heat removal from the debris, which would have been otherwise been sufficiently managed had the core been flooded. A modelling framework will also be developed within this proposal to investigate this safety aspect.The outcomes of this work will help scientists and engineers understand the processes during decommissioning activities as well as accident scenarios. They will help improve future designs and aid operators' responses to such events. In addition, they will help to enhance safety, limit damage and inform policy makers on design integrity. Importantly, the outcomes of this work will demonstrate to the public our commitment to safety in order to strengthen their confidence in nuclear technology.

现代计算代码可以非常有用地评估核电设施的行为，并确保它们在进入非预期运行情景时对公众、设施工人和环境造成的危害最小。该提案将开发此类方法，并将建立一个模拟工具，该工具准确，可靠，高效和有效，并能够确定我们可以对模型的信任程度。它将用于预测严重核事故后反应堆退役和清理的可能后果。它还寻求帮助建立先进的计算方法，以调查严重事故期间反应堆行为的各个方面。所提出的技术将有助于提供超出目前可能的准确性，并将允许探索无法通过实验复制的物理学。这里提出的工作旨在实现这一目标，通过开发一个基础，用于验证和验证的计算工具对基准的情况下，然后将用于模拟更复杂/现实的情况。该项目将联合收割机结合英国和日本在学术界和工业界的专门知识，调查严重核事故碎片退役的两个方面，以及预测事故期间堆芯材料的演变。堆芯材料的演变对退役很重要，因为它有助于确定反应堆内部结构的最终状态。由于福岛一个受损反应堆的状况，可能需要干式退役，即堆芯不被水淹没，这种新颖的燃料取出方法将在这里进行研究。干法去除的一个问题是，它引入了与释放到大气中的放射性粉尘相关的问题。当堆芯被打开，部分碎片被切割和清除时，会产生粉尘排放。这些颗粒会在空气中扩散和移动，因此会对现场人员和周围环境造成危险。为了减轻灰尘传播的严重性，将在核心周围部署细雾喷雾，以捕获和去除空气中的灰尘颗粒。将在此确定这种方法的适用性（以及是否保持对环境的充分屏蔽），并将开发先进的建模方法，以模拟反应堆内的粉尘扩散以及颗粒与水滴的相互作用。使用精细喷雾还可以通过提供从碎片的足够的热移除来克服关于干式移除的第二个问题，如果芯部被淹没，则这将被充分地管理。还将在本提案中制定一个模型框架，以调查这一安全问题，这项工作的成果将有助于科学家和工程师了解退役活动期间的过程以及事故情景。它们将有助于改进未来的设计，并帮助运营商应对此类事件。此外，它们还将有助于提高安全性，限制损害，并向决策者提供有关设计完整性的信息。重要的是，这项工作的成果将向公众表明我们对安全的承诺，以加强他们对核技术的信心。

项目成果

A combined immersed body and adaptive mesh method for simulating neutron transport within complex structures

用于模拟复杂结构内中子输运的组合浸入体和自适应网格方法

• DOI: 10.1016/j.anucene.2019.05.044
• 发表时间: 2019
• 期刊: Annals of Nuclear Energy
• 影响因子: 1.9
• 作者: Buchan A

Adaptive Haar wavelets for the angular discretisation of spectral wave models

用于谱波模型角度离散化的自适应 Haar 小波

• DOI: 10.1016/j.jcp.2015.10.046
• 发表时间: 2016
• 期刊: Journal of Computational Physics
• 影响因子: 4.1
• 作者: Adam A

A Point Kinetics Model of the Medical Isotope Production Reactor Including the Effects of Boiling

考虑沸腾效应的医用同位素生产反应堆的点动力学模型

• DOI: 10.13182/nse13-55
• 发表时间: 2017
• 期刊: Nuclear Science and Engineering
• 影响因子: 1.2
• 作者: Cooling C

Higher-order conservative interpolation between control-volume meshes: Application to advection and multiphase flow problems with dynamic mesh adaptivity

• DOI: 10.1016/j.jcp.2016.05.058
• 发表时间: 2016-09
• 期刊: J. Comput. Phys.
• 作者: A. Adam;D. Pavlidis;J. Percival;P. Salinas;Ziqing Xie;F. Fang;C. Pain;A. Muggeridge;M. Jackson

A comparison of element agglomeration algorithms for unstructured geometric multigrid

非结构化几何多重网格的元素聚集算法比较

• DOI: 10.1016/j.cam.2020.113379
• 发表时间: 2021
• 期刊: Journal of Computational and Applied Mathematics
• 影响因子: 2.4
• 作者: Dargaville S