CHaracterisation, Imaging and MaPping of fuel debris for safe retrieval (CHIMP)

用于安全检索的燃料碎片的表征、成像和绘图 (CHIMP)

基本信息

批准号：
EP/R01924X/1
负责人：
Claire Louise Corkhill
金额：
$ 32.27万
依托单位：
University of Sheffield
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FR01924X%2F1
关键词：
CHaracterisation Imaging MaPping fuel debris

项目摘要

This research is a joint UK and Japan effort to support ongoing clean-up operations at the Fukushima Daiichi Nuclear Power Plant (NPP). On March 11 2011, the tsunami that engulfed the Fukushima Daiichi NPP resulted in a loss of coolant accident and the partial meltdown of boiling water reactor Units 1 - 3. Immediately after the meltdown, seawater was injected into the high-temperature reactor cores for emergency cooling, however this was not sufficient and temperatures rose in excess of 2000C, causing pellets of UO2 nuclear fuel to melt and react with steam-oxidised zircaloy fuel cladding. The resulting material is highly hazardous and comprises a mixture of UO2 fuel, zirconium from the cladding and other melted reactor components, such as concrete and steel from the fuel pressure containment vessel. These materials are known as fuel debris and corium and are highly radioactive since they also incorporate fission products and minor actinides (e.g. plutonium) from the fission of the fuel. Since the accident, water has been continuously injected to the reactor, which has successfully cooled the fuel debris and corium. In this so-called "stable cold shutdown condition", analysis of coolant water effluent has been shown to contain plutonium, which indicates that the fuel debris is being dissolved. This has prompted significant efforts to retrieve the fuel debris and corium from the reactors, but before any plans for retrieval can be made, and technologies selected to safely undertake the retrieval operations, it is necessary to understand: 1) the chemical and physical properties of the fuel debris and corium; and 2) where the fuel debris and corium reside within the reactor.Because this material is not found in 'normal' nuclear decommissioning operations, and because it is not possible to enter the reactor to take samples, or to locate its position due to the extreme radiation field, other solutions are required. In this research project, we will make surrogate fuel debris and corium materials using UO2 doped with "cold" fission product analogues (e.g. stable isotopes), melted together with zirconium cladding and other reactor component materials (e.g. concrete and steel). In comparison with real fuel debris and corium, these will be safe to handle in the laboratory. By analysis of these materials, which will be the most realistic fuel debris and corium simulants created to date, we will build an understanding of their properties, which will support the choice of decommissioning methodologies (e.g. which type of robot and cutting tool) and how to handle the materials once they have been retrieved from the reactor. These materials will also be used to validate two important techniques currently under development by our Japanese project partners to retrieve fuel debris and corium from the reactors. The first is an on-site remote 3D imaging technique, capable of identifying the type of radioactive elements in any given piece of fuel debris or corium within the reactor, without direct contact. It is proposed to test this method during our project at the Fukushima Daiichi NPP. The second is a statistical mapping model, which will use input from the characterisation of our simulant fuel debris and corium materials, combined with data from the gamma radiation emission from the fuel debris within the Fukushima Daiichi NPP, to make a predictive map of where the fuel debris and corium reside within the reactor. This model, our materials and the collaboration between UK and Japan partners in this project, will strongly support the planning and implementation of safe fuel debris retrieval operations, which are due to begin in 2021.

这项研究是英国和日本共同的努力，旨在支持福岛Daiichi核电站（NPP）正在进行的清理运营。 2011年3月11日，吞噬福岛的海啸导致了冷却剂事故的损失，并且部分崩溃的水反应堆单位1-3。在崩溃后，海水被注入海水，将高温反应器注入高温反应堆中，但是这是急诊式冷却，并没有足够的核能，并在2000年的car ure2 cal of 2000 cal of 2000 cal of 2000c，in 2000 cel of us of us of 2000 cos of 2000 cos in 2000 cos in 2000 cose of 2000 c。并与蒸汽氧化的锆燃料燃料覆层反应。所得的材料是高度危险的，包括UO2燃料，甲壳层中的锆和其他熔化的反应器组件的混合物，例如燃料压力封装容器的混凝土和钢。这些材料被称为燃料碎片和石灰，是高分放射性的，因为它们还融合了燃料裂变中的裂变产物和次要肌动剂（例如plut）。自事故以来，水已不断注入反应堆，该反应堆已成功冷却了燃料碎屑和果质。在这种所谓的“稳定的冷门条件”中，对冷却液水废水的分析已显示出含p，这表明燃料碎屑正在溶解。这促使了从反应堆中检索燃料碎屑和石灰的巨大努力，但是在制定任何检索计划和选择安全进行检索操作的技术之前，有必要理解：1）燃料碎屑和果皮的化学和物理性质； 2）如果燃料碎屑和ri骨位于反应器中。因为在“正常”的核退役操作中找不到该材料，并且由于无法进入反应器采集样品，或者由于极端的辐射场而定位其位置，因此需要其他解决方案。在该研究项目中，我们将使用与“冷”裂变产物类似物（例如稳定的同位素）掺杂的UO2制造替代燃料碎片和石灰材料，并与锆层层层层层夹层和其他反应堆成分（例如混凝土和钢）融化。与实际的燃料碎屑和石灰相比，这些在实验室中可以安全处理。通过对这些材料的分析，这将是迄今为止创建的最现实的燃料碎屑和果皮模拟物，我们将建立对它们的性质的理解，这将支持选择退休方法的选择（例如，哪种类型的机器人和切割工具）以及如何在从反应堆中检索出材料后如何处理材料。这些材料还将用于验证我们的日本项目合作伙伴目前正在开发的两种重要技术，以从反应堆中检索燃料碎片和石灰。第一个是一种现场远程3D成像技术，能够识别反应堆内任何给定的燃料碎屑或果中的放射性元件的类型，而无需直接接触。建议在我们在福岛Daiichi NPP的项目中测试此方法。第二个是一个统计映射模型，该模型将使用我们的模拟燃料碎屑和核材料的表征中的输入，并结合福基岛daiichi NPP内燃料碎片的伽马辐射发射的数据，以预测反应器中的燃料碎屑位于燃料碎屑的位置。这种模型，我们的材料以及英国与日本合作伙伴在该项目中的合作，将强烈支持将于2021年开始的安全燃料碎屑检索操作的计划和实施。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Chemical state mapping of simulant Chernobyl lava-like fuel containing material using micro-focused synchrotron X-ray spectroscopy.

DOI：
10.1107/s1600577521007748
发表时间：
2021-11-01
期刊：
Journal of synchrotron radiation
影响因子：
2.5
作者：
Ding H;Dixon Wilkins MC;Mottram LM;Blackburn LR;Grolimund D;Tappero R;Nicholas SL;Sun S;Corkhill CL;Hyatt NC
通讯作者：
Hyatt NC

Synthesis, characterisation and preliminary corrosion behaviour assessment of simulant Fukushima nuclear accident fuel debris

模拟福岛核事故燃料碎片的合成、表征及初步腐蚀行为评估