In situ characterisation of liquids in decommissioning environments by LIBS

液体废物流和处置池是核退役挑战的关键部分。因此，这些环境的表征是一个重要的方面，采样和离线分析是传统的方法。该项目旨在研究使用激光诱导击穿光谱（LIBS），可以提供快速元素分析这些环境的原位表征。我们已经通过从液体表面测量证明了AFPC高温处理项目中熔盐初步测量的成功，但还有更多的问题需要回答，即采样是否代表散装以及将多变量数据分析和机器学习应用于衍生光谱。我们计划通过比较“试纸”采样和直接LIBS测量的试纸，以及LIBS探针的发展，直接采样的液体散装探索代表性的采样。后者将在室温环境下进行初步开发和试验。将与通过ICP离线测量的浸提样品进行比较。LIBS水下或熔盐探针测量特别具有挑战性，我们将利用我们在实验室中为TORONE项目（www.torone-project.com）的机器人应用构建的定制LIBS和拉曼系统的经验。该项目将利用NNL LIBS仪器，并设在CINDe实验室的NNL沃金顿。

Liquid waste streams and disposal ponds are key parts of the nuclear decommissioning challenge. Consequently, characterisation of these environments is an important aspect with sampling and off-line analysis being the conventional approach. This project aims to investigate the in situ characterisation of these environments using laser induced breakdown spectroscopy (LIBS) which can provide rapid elemental analysis. We have demonstrated success in preliminary measurements on molten salts in the AFPC-pyroprocessing project by measuring from the liquid surface but there are further questions to answer regarding whether the sampling is representative of the bulk as well as by applying multivariate data analytics and machine learning to the derived spectra. We plan to explore representative sampling by comparing 'dip-stick' sampling and direct LIBS measurement on the dip-stick as well as the development of a LIBS probe to directly sample the liquid bulk. The latter would be initially developed and trialled for ambient temperature environments. Comparisons will be made with extracted samples measured off-line by ICP. LIBS underwater or molten salt probe measurements are particularly challenging and we will build on the experience of the bespoke LIBS and Raman systems that we have built in our laboratory for robotic application on the TORONE project (www.torone-project.com). The project would make use of the NNL LIBS instrument and be based at NNL Workington in the CINDe laboratory.