Simultaneous Corrosion/Irradiation Testing in Lead and Lead-Bismuth Eutectic: The Radiation Decelerated Corrosion Hypothesis (RC-3)

铅和铅铋共晶的同步腐蚀/辐照测试：辐射减速腐蚀假说 (RC-3)

• 批准号: EP/T002808/1
• 负责人: Felix Hofmann
• 金额: $ 69.23万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FT002808%2F1
• 关键词: Simultaneous; Corrosion; Irradiation; Testing; Lead

Nuclear fission power plays a vital role in supplying the UK with low carbon footprint electricity. The current UK fleet of nuclear reactors is rapidly ageing, and all of these reactors are scheduled to be removed from service within the next 12 years. Without replacement, the electricity they generate, ~20% of total UK electricity, will need to be provided by other sources, e.g. fossil fuel power stations. This would be detrimental to UK greenhouse gas emissions and contribution to climate change. For successful decarbonisation by the 2050s, UK new build of future fission reactors is urgently needed. Liquid lead (Pb) and lead-bismuth eutectic (LBE) cooled fast reactors promise the best power density and economics among fission reactors. However, for decades now the development of these reactors has been stuck because of concerns about the combined effect of Pb/LBE corrosion and irradiation on the structural materials they would use. Moreover, the problem is that to actually test how bad the corrosion is, one would either have to setup an experiment in an existing research reactor or indeed build a whole new Pb or LBE-cooled research reactor. This would be prohibitively costly, slow and it would be challenging to build and license a test reactor without initial understanding and prediction of material performance. A much faster way of studying combined irradiation and corrosion of materials for Pb/LBE cooled fast reactors is needed!Here we address this problem: Our project partners at MIT, USA, have developed a new, one-of-a-kind facility that allows the simultaneous exposure of materials to Pb/LBE corrosion and insitu irradiation with protons. The protons are used to mimic the effect of neutrons in a fission reactor. Whilst protons don't perfectly mimic the damage caused by neutrons, they capture the key mechanisms well. Most importantly these experiments are much quicker and cheaper than e.g. in-reactor material testing. Using this new tool, we will explore the performance of five of the current front-runner alloys for cladding and structural components in Pb/LBE fast reactors. We will also compare the results against more traditional Pb/LBE corrosion tests to make sure the new combined irradiation and corrosion facility performs as anticipated. After exposure, the Oxford partners of the project team will then analyse the samples to determine how Pb/LBE corrosion proceeds in the presence of irradiation, and how this differs from Pb/LBE corrosion without irradiation. Curiously our initial results show that irradiation slows down the rate of corrosion! To explore and understand this behaviour, we will perform characterisation of the structure and chemical composition of samples after exposure, from the macroscopic down to the atomic scale. This microstructural characterisation will be combined with mechanical testing of the exposed materials carried out by US project partners at the North Carolina State University. Overall the results from this project will finally address how simultaneous irradiation modifies the corrosion behaviour of alloys for Pb/LBE cooled fast reactors. It will allow us to identify which of the tested candidate alloys performs best and what the key mechanisms are that control its degradation during combined corrosion and irradiation. This information is vital for overcoming the current stagnation of progress in the development of Pb/LBE cooled fast reactors, and to allow directed optimisation of the structural and cladding materials they require.

核裂变发电在为英国提供低碳足迹电力方面发挥着至关重要的作用。目前英国的核反应堆正在迅速老化，所有这些反应堆都计划在未来 12 年内退役。如果不进行替代，它们产生的电力（约占英国总电力的 20%）将需要由其他来源提供，例如：化石燃料发电站。这将不利于英国温室气体排放和气候变化。为了到 2050 年代成功实现脱碳，英国迫切需要新建未来裂变反应堆。液态铅 (Pb) 和铅铋共晶 (LBE) 冷却快堆有望成为裂变反应堆中最佳的功率密度和经济性。然而，几十年来，由于担心 Pb/LBE 腐蚀和辐射对其使用的结构材料的综合影响，这些反应堆的开发一直停滞不前。此外，问题在于，要实际测试腐蚀有多严重，要么必须在现有研究堆中进行实验，要么建造一个全新的铅或 LBE 冷却研究堆。这将是昂贵且缓慢的，并且在没有对材料性能进行初步了解和预测的情况下建造和许可测试反应堆将具有挑战性。需要一种更快的方法来研究 Pb/LBE 冷却快堆材料的组合辐照和腐蚀！在这里，我们解决这个问题：我们在美国麻省理工学院的项目合作伙伴开发了一种新的、独一无二的设施，允许材料同时暴露于 Pb/LBE 腐蚀和质子原位辐照。质子用于模拟裂变反应堆中中子的效应。虽然质子不能完美地模拟中子造成的损伤，但它们可以很好地捕捉关键机制。最重要的是，这些实验比例如实验更快、更便宜。反应堆内材料测试。使用这一新工具，我们将探索目前用于 Pb/LBE 快堆包壳和结构部件的五种领先合金的性能。我们还将把结果与更传统的 Pb/LBE 腐蚀测试进行比较，以确保新的辐照和腐蚀组合设施按预期运行。暴露后，项目团队的牛津合作伙伴将分析样品，以确定在辐照情况下 Pb/LBE 腐蚀如何进行，以及这与无辐照情况下的 Pb/LBE 腐蚀有何不同。奇怪的是，我们的初步结果表明，辐照可以减缓腐蚀速度！为了探索和理解这种行为，我们将对暴露后样品的结构和化学成分进行表征，从宏观到原子尺度。这种微观结构表征将与美国北卡罗来纳州立大学项目合作伙伴对暴露材料进行的机械测试相结合。总体而言，该项目的结果将最终解决同时辐照如何改变 Pb/LBE 冷却快堆合金的腐蚀行为。它将使我们能够确定哪种测试的候选合金表现最好，以及控制其在腐蚀和辐照联合作用期间降解的关键机制是什么。这些信息对于克服目前 Pb/LBE 冷却快堆开发进展停滞的问题，以及对其所需的结构和包壳材料进行定向优化至关重要。

项目成果

Characterisation of corrosion damage in T91/F91 steel exposed to static liquid lead-bismuth eutectic at 700-715 °C

T91/F91钢在700-715℃静态液态铅铋共晶中的腐蚀损伤表征

• DOI: 10.1016/j.jnucmat.2023.154687
• 发表时间: 2023
• 期刊: Journal of Nuclear Materials
• 影响因子: 3.1
• 作者: Lapington M

Characterisation of Corrosion Damage in T91/F91 steel exposed to Liquid Lead-Bismuth Eutectic

T91/F91 钢在液态铅铋共晶中的腐蚀损伤表征

• DOI: 10.48550/arxiv.2302.03470
• 发表时间: 2023
• 作者: Lapington M