Advanced chemistry and corrosion studies under hot water conditions relevant to LWR coolant

这名学生将在NNL的Tomas Martin博士、奥利弗佩顿博士和Rob Burrows博士的监督下，使用先进材料特性研究核反应堆钢的热水腐蚀。英国的下一代核反应堆，从欣克利角C开始，将避开英国特有的气冷式设计，而采用其他核电国家更常见的水冷式反应堆。这些轻水反应堆（LWR）将有显着不同的组件和操作设计，因此，这些组件中的腐蚀，应力和疲劳机制将与英国工业界和学术界目前研究的机制截然不同。类似的加压水冷却系统将用于聚变反应堆，如ITER和DEMO，并将有许多相同的腐蚀问题。这个博士项目将调查贵金属添加到沸水反应堆（BWR）的冷却剂的影响，如在英国Wylfa和Oldbury提出的那些。BWR具有应力腐蚀开裂（SCC）的历史问题，其中来自水冷却剂的腐蚀导致部件在机械应力下开裂。在美国，通过改变冷却剂水的化学性质，向水中注入氢、锌和铂以减少辐解的影响并限制自由基物质来缓解该问题。虽然已证实添加这些物质有助于防止运行反应堆中应力腐蚀裂纹的增长，但在调试和测试期间，对新反应堆上这种变化的水化学的研究很少，该项目将与NNL合作开发一个高压釜测试设施，并将一系列钢和镍合金暴露于LWR水条件和各种水化学物质中，更好地理解腐蚀背后的机理及其通过贵金属注入的抑制作用。这些样品将采用各种最先进的表面和材料分析技术进行表征，包括电子显微镜、电子背散射衍射、X射线衍射和聚焦离子束铣削。通过创建应力材料的小杠杆，局部SCC的影响将使用高分辨率化学绘图工具，如透射电子显微镜和原子探针断层扫描进行探索。除了使用高压釜腐蚀实验的主要研究工作外，该项目还将使用NanoESCA结合使用高速原子力显微镜在液体电池中进行腐蚀实时成像的功函数电子映射来探索纳米级腐蚀机制。

This student will be investigating hot water corrosion of nuclear reactor steels using advanced materials characterisation, under the supervision of Dr Tomas Martin, Dr Oliver Payton and Dr Rob Burrows of NNL. The next generation of nuclear reactors in the UK, beginning with Hinckley Point C, will eschew the UK-specific gas-cooled design for the water-cooled type of reactor more commonly found in other countries with nuclear power. These light water reactors (LWR) will have significantly different components and operational design, and as such the mechanisms of corrosion, stress and fatigue in these components will be dramatically different from those currently studied in UK industry and academia. Similar pressurised water cooling systems will be used for fusion reactors such as ITER and DEMO, and will have many of the same corrosion issues.This PhD project will investigate the effects of noble-metal addition to the coolant of Boiling Water Reactors (BWRs) such as those proposed at Wylfa and Oldbury in the UK. BWRs have had a historical issue with stress corrosion cracking (SCC), where corrosion from the water coolant results in cracking of components under mechanical stress. In the USA, this problem is mitigated by changing the coolant water chemistry, injecting hydrogen, zinc and platinum to the water to reduce the effect of radiolysis and limit free radical species. Whilst the addition of these species has been confirmed to help prevent the growth of stress corrosion cracks in operational reactors, there has been little investigation of this changed water chemistry on new reactors during commissioning and testing, and on the The project will develop an autoclave testing facility in partnership with NNL and expose a series of steel and nickel alloys to LWR water conditions and a variety of water chemistries to better understand the mechanism behind corrosion and its inhibition by noble metal injection. These specimens will be characterised with a wide range of state-of-the-art surface and materials analysis techniques, including electron microscopy, electron backscatter diffraction, X-ray diffraction and focused ion beam milling. By creating small cantilevers of stressed material, the effect of localised SCC will be explored using high resolution chemistry mapping tools such as transmission electron microscopy and atom probe tomography. In addition to the main research work using autoclave corrosion experiments, the project will probe the mechanism of corrosion at the nanoscale using electronic mapping of the workfunction using the NanoESCA combined with live imaging of corrosion using high-speed atomic force microscopy in a liquid cell.