Platform for Long-term Experimental Investigation of Alteration in Disposal Environments and Storage - PLEIADES

PLEIADES将建立必要的研究基础设施，以支持对遗留、新建和未来核燃料循环产生的放射性材料进行退役、临时储存和处置安全案例的开发。它将使与核能有关的政府政策的三个关键领域的研究成为可能：地质处置：英国政府的核退役责任的成功及其未来的新建设雄心取决于政策的成功实施，以提供放射性废物的地质处置设施（GDF）。有必要证明，在建造GDF之前，将保持其关闭后的安全性。这需要了解在GDF条件下废物的长期腐蚀速率和降解机制，而PLEIADES将独特地提供这些。2. 减少遗留核设施的危害：英国遗留核设施退役的风险和危害是世界上最具挑战性的。在退役期间，放射性废物被转化为可以安全储存数十年的形式。在贮存过程中，废料不应发生变化或降解，但有许多废料易受腐蚀。PLEIADES内的设备将有能力确定这些放射性材料的腐蚀过程和速率，为临时储存的安全案例提供信息，并为未来的管理实践提供后续决策。加速核退役：最近有消息称，要想在2030年前为英国纳税人节省1200亿英镑的核退役成本中的20%，首选的解决方案是开发至少一个近地表处置（NSD）设施。在NSD处置废物可大大缩短退役时间表。这种新方法取得成功的关键是对NSD安全性的评估，包括放射性废物在100年处置过程中的降解模型。PLEIADES有能力解决这些设施中废物的腐蚀和放射性核素释放率方面的关键知识空白，从而支持加速实施NSD。PLEIADES将是英国一个独特的设施，使研究能够解决学术界和放射性废物管理行业确定的关键能力差距：>地下处理条件下的腐蚀：由于放射性材料对大气条件高度敏感，因此在实验室中复制地下处理环境至关重要。只有在腐蚀实验过程中保持正确的条件，才能获得有意义的数据。“昴宿星”的设备将能够对广泛的无线电材料进行这样的研究，这是目前英国没有能力做到的。长期腐蚀：PLEIADES的一个独特之处在于能够在具有代表性的地下环境的稳定条件下建立长期（数十年）腐蚀实验，从而详细了解缓慢的降解过程。在距离GDF建成不到20年的时间里，如果我们要了解放射性废物腐蚀背后的科学，现在建立长期实验是至关重要的。>辐射场内的腐蚀：放射性材料的腐蚀过程会受到辐射效应的显著影响。由于缺乏能够对其进行调查的设施，目前对这些影响知之甚少。PLEIADES将成为英国唯一具备分析高放射性物质能力的大学设施，这些高放射性物质会产生自己的辐射场，并且PLEIADES设备与其他用户设施兼容，可以在外部辐射场内进行腐蚀实验。

PLEIADES will establish essential research infrastructure to underpin the development of decommissioning, interim storage and disposal safety cases for radio-materials arising from legacy, new build and future nuclear fuel cycles. It will enable research in 3 key areas of government policy relating to nuclear energy:1. Geological disposal: The success of HM Government's nuclear decommissioning responsibilities and its future new build ambitions rests upon the successful implementation of policy to deliver a geological disposal facility (GDF) for radioactive waste. It is necessary to demonstrate that post-closure safety of a GDF will be maintained before it can be built. This requires an understanding of long-term corrosion rates and degradation mechanisms of waste, under GDF conditions, which PLEIADES will be uniquely placed to provide. 2. Reduce hazard of legacy nuclear sites: The risks and hazards of decommissioning the UK's nuclear legacy are the most challenging in the world. During decommissioning, radioactive wastes are converted into a form that can be safely stored for many decades. During storage, the waste materials should not change or degrade, however, there are many that are subject to corrosion. The equipment within PLEIADES will have the capability to determine the corrosion processes and rates of such radio-materials, informing safety cases for interim storage and subsequent decisions about future management practice.3. Accelerate nuclear decommissioning: It was recently announced that the preferred solution to deliver savings of 20% in the £120 billion cost of nuclear decommissioning to the UK taxpayer, by 2030, is the development of at least one Near Surface Disposal (NSD) facility. Disposal of waste in NSD could dramatically reduce decommissioning timescales. Pivotal to its success of this new approach is an appraisal of NSD safety, including models of radioactive waste degradation over the 100s of years of disposal. PLEIADES has the capability to address critical knowledge gaps in corrosion and radionuclide release rates from waste in such facilities and, therefore, to support accelerated implementation of NSD.PLEIADES will be a unique facility in the UK, enabling research that addresses key gaps in capability that were identified by the academic community and radioactive waste management industry: > Corrosion in sub-surface disposal conditions: Because radio-materials are highly sensitive to atmospheric conditions it is essential that sub-surface disposal environments are replicated in the laboratory. Only if the correct conditions are maintained during corrosion experiments will meaningful data be obtained. The PLEIADES equipment will enable such research on a wide range of radio-materials, for which is there is no current UK capability.> Long-term corrosion: A unique aspect of PLEIADES is the capability to establish long-term (decades) corrosion experiments under stable conditions representative of sub-surface environments, giving detailed insight to slow degradation processes. With less than 20y remaining until a GDF will be constructed, the establishment of long-term experiments is essential now, if we are to understand the science behind radioactive waste corrosion.> Corrosion within a radiation field: Corrosion processes of radio-materials can be significantly influenced by the effects of radiation. These effects are currently poorly understood because there is a paucity of facilities that enable their investigation. PLEIADES will constitute the only UK university facility with capability for analysing highly radioactive materials that create their own radiation field, and the PLEIADES equipment is compatible other user facilities that will enable corrosion experiments to be performed within an external radiation field.