NANOstructured Beta Detectors for Detection Of Tritium (NANODOT)

氚是氢的一种放射性同位素，由核裂变反应以及腐蚀、辐射分解和微生物过程对放射性废物的作用产生。它通过平均动能为5.7keV的软β衰变衰变到He-3。这种低能量使得即使通过闪烁计数也很难检测到。除其他外，以下方面需要对气态氚进行快速、准确和精确的测量：围绕较高放射性废物临时储存地点的环境监测和泄漏检测；为这些废物的地质储存库编制环境安全案例；在核反应堆和核燃料加工厂内和周围进行环境和安全监测；以及核取证，包括在反恐、国土安全和不扩散方面的应用。钯是一种金属，它显示出几乎独特的能力，可以将氢吸收到其晶体基质中。市场上有许多基于氢与钯金属相互作用的商用氢传感器，其中大多数通过测量金属电容或电阻来量化这种吸收。到目前为止，还没有人探索过利用独特的Pd-H相互作用作为一种手段来选择性地从气相样品基质中预富集氚的可能性，以便改进使用Pd修饰的闪烁探测器的检测。因此，我们建议利用纳米材料合成中的新概念，使我们能够将纳米孔钯层修饰的换能器/闪烁计数器与从电离辐射事件中捕获的数字化数据结合起来，以开发一种新的基于辐射传感器的气态氚测量系统。使用纳米孔钯将增加可用于氚吸收的金属表面积，而使用数字化数据捕获将允许捕获整个数据集，以供后代和后处理。这两项措施都有望提高信噪比，有助于实现更低的检测下限，从而提高测量的准确度和精确度。在为上述应用开发这种传感器时，拟议的工作涉及以下NERC主题行动计划(TAP)：技术；环境、污染和人类健康；以及自然灾害。我们的目标是将传感器系统开发到技术准备级别5(演示)。该项目是兰开斯特大学工程系和兰开斯特环境中心(LEC)以及兰开斯特衍生的混合仪器公司之间的合作项目。国家核实验室(曾是其前身项目的合作伙伴)和核退役管理局放射性废物管理局将是关键的最终用户。

Tritium is a radioactive isotope of hydrogen that is produced from nuclear fission reactions and from the action of corrosion, radiolytic and microbial processes on radioactive wastes. It decays to He-3 by soft beta decay of average kinetic energy 5.7 keV. This low energy makes it difficult to detect even by scintillation counting. Fast, accurate and precise measurement of gaseous tritium is required for, inter alia: environmental monitoring & leak detection around interim storage sites for higher level radioactive wastes; development of the environmental safety case for the geologic repository for those same wastes; environmental and safety monitoring in and around nuclear reactor and nuclear fuel processing plant; and nuclear forensics, including applications in counter-terrorism, homeland security and non-proliferation. Palladium is a metal that shows an almost unique capacity for absorbing H2 into its crystal matrix. There are a number of commercial H2 sensors on the market based on the interaction of H with palladium metal, most of which quantify this uptake by measurement of the metal capacitance or resistance. No one to date has explored the possibility of exploiting the unique Pd-H interaction as a means to selectively preconcentrate tritium from gas phase sample matrices in order to improve its detection using a Pd-modified scintillation detector. We therefore propose to exploit new concepts in nanomaterials synthesis to allow us to couple nanoporous palladium layer-modified transducers / scintillation counters and digitized data capture from ionizing radiation events to develop a novel radiometric sensor-based measurement system for gaseous tritium detection. The use of nanoporous palladium will increase the surface area of metal available for tritium absorption whilst the use of digitised data capture will allow for whole data sets to be captured for posterity and post-processing. Both measures are expected to lead to improved signal to noise ratios assistive to the achieving of lower limits of detection and so greater accuracy and precision in measurement. In developing this sensor for the applications mentioned above , the proposed work addresses the following NERC Theme Action Plans (TAPs):Technologies; Environment, Pollution & Human Health; and natural Hazards. We aim to develop the sensor system through to Technology Readiness Level 5 (Demonstration). This project is a partnership between the Engineering Dept and the Lancaster Environment Centre (LEC) at Lancaster University and Hybrid Instruments, a Lancaster spin-out. The National Nuclear Laboratory (who have served as partners on predecessor projects to this), and the Nuclear Decommissioning Authority Radioactive Waste Management Directorate will be a key end user.