A Diamond Detector for Monitoring Of Neutron Irradiation and Criticality

需要新型探测器仪器系统来支持基于裂变或聚变技术的核电站的运行和退役。在这个项目中，人造金刚石将被用作辐射探测器，用于测量伽马和中子辐射。这个项目将把一种经过验证的探测器商业化，该探测器已被用于在世界上一些最危险的建筑物内进行测量，这些建筑物存在裂变和放射性物质。基于大型强子对撞机首次使用的金刚石技术，这个商业化项目将采用由布里斯托大学和塞拉菲尔德大学开发的可操作的原理验证示范器的技术（并在后处理罐内使用）转换为一系列产品，这些产品将由卡文迪什核有限公司作为一项服务运营。为了实现商业化，该项目已得到英国、日本和意大利的工业界和学术界的广泛支持。这个国际团队的每个成员都带来了具体的专业知识和设施，从京都大学的核研究反应堆，我们将展示探测器测量反应堆功率输出的能力（通过中子通量测量），到塞拉菲尔德的高活性储罐，我们将展示实时高伽马剂量率测量。我们的工业合作伙伴要求重点关注中子探测，这是他们目前正在努力利用现有技术实现的一项重要能力。中子探测对于防止意外临界和从任何此类事件中恢复至关重要。我们的日本合作伙伴特别要求这种能力，使他们能够安全地从福岛第一核电站受损的核反应堆中取出燃料，这将有助于英国安全储存裂变材料的设施。任何储存裂变材料的工业设施都需要临界事件探测系统，以减轻发生意外临界时对人员的风险。这必须检测到临界状态，并在发生连锁事件时继续测量。仍需要进一步的测试和开发，但用更便宜、更紧凑和更强大的替代品取代现有CIDS技术的潜力令人兴奋。中子探测和伽马探测是非常需要的：在初始事件之后，任何现有设备都不能测量持续的脉冲/连续临界;便携式系统在手套箱和大型设施中有许多应用。同样需要在反应堆堆芯环境（裂变和聚变）中进行快速中子探测，其中中子通量更加持续和强烈。金刚石非常适合这种应用，其对热中子和快中子的敏感性已被证明优于伽马辐射。因此，本建议的目的是开发一种金刚石探测器系统，其能够在操作员和探测电子设备处于安全的远程工作距离的情况下，真实的实时地探测中等到高的中子通量。这将建立在已经为高剂量伽马测量开发的软件和硬件的基础上，增加探测系统的价值。这种技术对于第四代裂变反应堆概念（包括小型模块化反应堆）以及未来的聚变反应堆（包括JET、ITER和DEMO项目）以及英国原子能机构最近宣布的商业能源生产小型托卡马克（STEP）计划都将是非常宝贵的。从长远来看，通过光谱学测量中子能量将有助于使聚变技术成为现实。我们不仅可以使用在这个项目中开发的金刚石中子探测器来测量反应堆的功率（如上所述），而且我们还可以证明运行中的聚变反应堆通过增殖自己的燃料在氚方面是自给自足的！

Novel detector instrumentation systems are required to support the operation and decommissioning of our nuclear power stations, either based on fission or fusion technologies. In this project, synthetic diamond will be used as a radiation detector for the measurement of gamma and neutron radiation.This project will commercialise a well-proven detector which has been used to make measurements inside some of the most hazardous buildings in the world, where fissile and radioactive materials are present.Based on diamond technology first used in the Large Hadron Collider, this commercialisation project will take the technology from operational proof-of-principle demonstrators developed by the University of Bristol and Sellafield (and used inside reprocessing tanks) to a series of products which will be operated as a service by Cavendish Nuclear Limited.To achieve commercialisation, this project has solicited support from a wide range of industrial and academic partners in the UK, Japan and Italy. Each member of this international team brings specific expertise and facilities, from Kyoto University's nuclear research reactor, where we will demonstrate the detector's capability to measure the reactor's power output (through neutron flux measurement), to Sellafield's Highly Active Storage Tanks, in which we will demonstrate real-time high gamma dose rate measurement. Our industrial partners have requested a focus on neutron detection, an important capability they are currently struggling to achieve using existing technology. Neutron detection will be important to prevent accidental criticality and recover from any such event. Our Japanese partners have specifically requested this capability to allow them to safely remove the fuel from within the stricken nuclear reactors at Fukushima Daiichi, and it will be useful in UK facilities safely containing fissile material. A Criticality Incident Detection System (CIDS) is needed in any industrial facility holding fissile material, to mitigate risks to personnel in the event of an accidental criticality. This must detect a criticality and continue to measure afterwards in case of knock-on events. Further testing and development are still needed, but the potential for superseding existing CIDS technologies with a cheaper, more compact and robust alternative is exciting. Neutron detection alongside gamma detection would be highly desirable: on-going pulsed/continuous criticality is not measured by any current devices after an initial event; and there are a multitude of applications in gloveboxes and large facilities for a portable system.There is equally a need for rapid neutron detection in reactor core environments (fission and fusion), where the neutron flux is far more sustained and intense. Diamond is potentially very well-suited to such applications, with a proven sensitivity to thermal and fast neutrons better than that of gamma radiation. Accordingly, the aim of the current proposal is to develop a diamond detector system capable of detecting moderate-to-high neutron fluxes in real time, with the operator and detection electronics at a safe remote working distance. This will build on the software and hardware already developed for high-dose gamma measurement, increasing the value of the detection system. Such technology will be invaluable for Gen IV fission reactor concepts, including small modular reactors, as well as future fusion reactors, including JET, ITER and DEMO projects, and the UKAEA's recently announced Small Tokomak for commercial Energy Production (STEP) programme.Longer term, the measurement of neutron energies through spectroscopy will help enable fusion technologies to become realistic. Not only can we use the diamond neutron detectors being developed in this project to measure the reactor power (as above), but we will also be able to demonstrate that the operational fusion reactor is self-sufficient in tritium by breeding its own fuel!