The impact of polyacrylamide radiolytic and microbial degradation products on the interim and long term storage on radwaste

聚丙烯酰胺已被确定为一种潜在的沉淀剂，它可以通过在塞拉菲尔德工厂对一系列遗留燃料材料进行絮凝来改善污泥沉降操作。微生物将聚合物分解成可能被产甲烷菌消耗的底物，从而产生甲烷和二氧化碳。预计聚丙烯酰胺将增加微生物种群并增加此类气体的生成，同时还提供辐射分解和生物降解途径，以生产能够螯合和动员被判处长期地质处置的放射性核素的材料。了解放射性分解和微生物降解产物和动力学将为工程设计能力提供信息，并向退役和处置利益攸关方告知如何在核退役作业中应用和管理此类试剂的风险。这个跨学科的研究项目将结合地球微生物学、微生物基因组学、有机化学、放射化学和辐射科学，并将使用最先进的技术，包括微生物和DNA测序分析、光学和电子显微镜、XRF、XAS、共聚焦显微镜、环境扫描电子显微镜和透射电子显微镜，在批量实验室孵化中研究聚丙烯酰胺(生物)的降解。成功的申请者将加入一个由40名跨学科研究人员组成的欢迎队伍，他们在地球和环境科学部最近翻修和合用的两个中心工作，由国际和平研究所和共同主管(劳埃德、莫里斯、范东恩和肖)共同指导。学生将有机会进入威廉姆森分子环境科学研究中心内的一大套专门实验室，该中心拥有最先进的分子环境研究设备，并与新的GB 4M NNUF雷达实验室(https://www.nnuf.ac.uk/rader))并排而坐，由莫里斯领导，为处理和分析核环境系统中的放射性核素提供独特的补充设施。学生还将受益于与道尔顿坎布里安设施(DCF)的链接，以进行关于聚丙烯酰胺的辐射研究。

Polyacrylamide has been identified as a potential settling aid which can improve sludge settling operations by flocculating a range of legacy fuel materials on the Sellafield site. Microbes break down polymeric material into substrates which may potentially be consumed by methanogens, producing methane and carbon dioxide. Polyacrylamide is expected to increase the microbial population and increase the generation of such gases, while also providing radiolytic and biological degradation paths to produce material which could chelate and mobilse radionuclides sentenced to a long-term geological disposal. Understanding the radiolytic and microbial degradation products and kinetics will inform engineering design capability, and inform decommissioning and disposal stakeholders how to apply and manage risk regarding the application of such reagents in nuclear decommissioning operations. This interdisciplinary research project will combine geomicrobiology, microbial genomics, organic chemistry, radiochemistry, and radiation science, and will study polyacrylamide (bio)degradation in batch laboratory incubations using state of the art techniques including microbial and DNA sequencing analysis, light and electron microscopy, XRF, XAS, confocal microscopy, ESEM, and TEM. The successful applicant will join a welcoming cohort of 40+ interdisciplinary researchers working in two recently refurbished and co-located centres in the Dept of Earth and Environmental Sciences, co-directed by the PI and co-supervisors (Lloyd, Morris, van Dongen and Shaw). The student will have access to a large suite of dedicated laboratories within the Williamson Research Centre for Molecular Environmental Sciences (WRC; directed by Lloyd), which houses state of the art equipment for molecular environmental studies and sits alongside the new £4M NNUF RADER labs (https://www.nnuf.ac.uk/rader) directed by Morris, offering unique complementary facilities for handling and analysing radionuclides in nuclear environmental systems. The student will also benefit from links to the Dalton Cumbrian Facility (DCF) for irradiation studies on polyacrylamide.