Reactor core-structure re-location modelling for severe nuclear accidents

严重核事故的反应堆堆芯结构重新定位模型

• 批准号: EP/M012794/1
• 负责人: Christopher Pain
• 金额: $ 31.1万
• 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: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FM012794%2F1
• 关键词: Reactor; core; structure; re; location

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 is to develop such methods, as well as to 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 seeks to help establish advanced computational methods to address problems in fault conditions, as well as to investigate aspects of system behaviour in severe accident situations. It 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.The specific situation that this project intends to investigate is in a civil reactor's response to severe accident scenarios following a loss of its coolant. Under such situations internal structures can be compromised and the melting of control rods and/or fuel pins may occur. In extreme situations whole sections of the core may melt resulting in large quantities of molten materials accumulating in the vessel's lower head. In all these situations the relocation of the core's materials will affect the functioning of the reactor. There is a possibility of achieving a sustained critical reaction, resulting in extensive heating, and the coolant flows will be diverted thus preventing the heat removal from parts of its core. In addition, chemical reactions can occur, some of which pose significant hazards. Examples include oxidation processes between the air and/or steam with the fuel cladding (zirconium in particular) or control rod materials resulting in hydrogen production - as what occurred in Fukushima.The aims of this project will be to develop a generic framework for accident modelling and validate it through the study of control rod and fuel pin melt. A computer model will be built capable of resolving, in unprecedented detail, the melting, relocating and re-solidification process of the pins when overheated. The objectives are to build the specialist numerical tools that enable the complex physics and chemistry to be resolved. The objective also includes a validation process by a comparison with experiment. This will be through collaboration with academics and industry in Japan.The outcomes of this work will help scientists and engineers understand the processes during accident and melting 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 regain or 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。这项建议是开发这样的方法，以及建立一个模拟工具，是准确的，强大的，有效的和验证，并能够确定的信心水平，我们可以放在模型上。它旨在帮助建立先进的计算方法，以解决故障条件下的问题，以及调查在严重事故情况下系统行为的各个方面。它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与英国和日本的学术界和工业界的专业知识相结合。该项目旨在研究民用反应堆在失去冷却剂后发生严重事故时的具体情况。在这种情况下，内部结构可能受到损害，并且可能发生控制棒和/或燃料细棒的熔化。在极端情况下，堆芯的整个部分可能熔化，导致大量熔融材料积聚在容器的下封头中。在所有这些情况下，核心材料的重新定位将影响反应堆的功能。有可能实现持续的临界反应，导致广泛的加热，冷却剂流将被转移，从而防止热量从其核心的一部分。此外，可能发生化学反应，其中一些会造成重大危害。例子包括空气和/或蒸汽与燃料包壳（特别是锆）或控制棒材料之间的氧化过程，从而产生氢气-就像在福岛发生的那样。将建立一个计算机模型，能够解决，在前所未有的细节，熔化，重新定位和重新凝固过程中的引脚过热。目标是建立专业的数值工具，使复杂的物理和化学得到解决。目标还包括通过与实验的比较来验证过程。这项工作将通过与日本学术界和工业界的合作进行，其成果将有助于科学家和工程师了解事故和融化情景下的过程。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，以恢复或加强他们对核技术的信心。

项目成果

Goal-based angular adaptivity applied to a wavelet-based discretisation of the neutral particle transport equation

• DOI: 10.1016/j.jcp.2014.10.063
• 发表时间: 2015-01
• 期刊: J. Comput. Phys.
• 作者: Mark A. Goffin;A. Buchan;S. Dargaville;C. Pain;Paul N. Smith;R. Smedley-Stevenson

An efficient space-angle subgrid scale discretisation of the neutron transport equation

• DOI: 10.1016/j.anucene.2016.03.012
• 发表时间: 2016-08
• 期刊: Annals of Nuclear Energy
• 影响因子: 1.9
• 作者: A. Buchan;C. Pain

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

Goal-based angular adaptivity applied to the spherical harmonics discretisation of the neutral particle transport equation

• DOI: 10.1016/j.anucene.2014.03.030
• 发表时间: 2014-09
• 期刊: Annals of Nuclear Energy
• 影响因子: 1.9
• 作者: Mark D Goffin;Andrew D Buchan;Anca Belme;Christopher P Pain;M. D. Eaton;Mark A. Goffin;A. Buchan;A. Belme;Christopher C. Pain;Paul N. Smith;R. Smedley-Stevenson

Solving the Boltzmann transport equation with multigrid and adaptive space/angle discretisations

使用多重网格和自适应空间/角度离散求解玻尔兹曼输运方程

• DOI: 10.1016/j.anucene.2015.02.014
• 发表时间: 2015
• 期刊: Annals of Nuclear Energy
• 影响因子: 1.9
• 作者: Dargaville S