DIAMOND: Decommissioning, Immobilisation And Management Of Nuclear wastes for Disposal

保守估计，英国过去60年民用核计划遗留下来的废物处理和处置，以及退役和场地补救，为英国纳税人带来了700亿英镑的成本。在解决这一问题时必须解决的问题种类繁多，需要从同样广泛的技术学科领域中提出一系列创新的解决办法。拟议的研究计划分为三个工作包(WPS)：(1)环境、迁移和风险；(2)退役、历史遗产和场地终止；(3)材料-设计、开发和性能。WP 1：环境、迁移和风险清理受污染的土地是核电站恢复的重要组成部分。目前存在的放射性污染物的范围以及混合污染的可能性是一个重大挑战。特别是，可溶物质和胶体物质在地下的迁移潜力是确定场地终点的关键不确定性。目前，预计大多数清理工作将通过侵入性技术进行；因此，我们将探索更具成本效益的就地技术，如屏障处理系统。与固定化放射性废物地质处置有关的许多不确定性和技术挑战严重取决于工程设施的释放率，以及随后放射性核素在扰动区和远场的行为。工作包2：退役、历史遗产和场地终结燃料储存和处理设施中存在的异质废物是该联盟的主要目标。这些废物包括经辐射的燃料、受污染的材料和腐蚀产物。总容量和组成(化学和放射性)鲜为人知，尽管据信每个主要储水池中都有数百立方米。因此，改进和准确的特征描述是当务之急，这里提出了检索和治疗的新技术。此外，历史活动产生了少量的孤儿废物，没有明确的管理路线；它们的多样性需要新的和多样化的处理方法，这将在本方案中制定。我们还专注于放射性核素库存的量化、通过工程路径的污染物运输和废物回收，作为我们可以做出进一步贡献的领域。工作包3：材料-设计、开发和性能地质处置已被政府接受为英国放射性废物长期管理的最佳可用方法，并得到一个强有力的临时储存计划的支持。因此，本工作方案的研究重点是解决废物调理、储存和处置方面的关键知识空白，以便为今后的废物管理决策奠定基础。研究基于三个关键主题，旨在：1)了解辐射和辐射分解对临时储存期间核陶瓷稳定性的影响；2)了解乏核燃料、钢包装和高放废物玻璃在储存和处置条件下的腐蚀机理；3)开发新材料和处理路线，使其能够灵活地以适合储存和处置的形式固定包括燃料碎片和石墨在内的各种废物。这一可湿式燃料的另一个方面将是开发新的合成路线，以获得先进的惰性基质燃料。

Legacy waste treatment and disposal, as well as decommissioning and site remediation, from the last 60 years of the UK's civil nuclear program are conservatively estimated at a cost of 70B for the UK taxpayer. The diversity of issues that must be addressed in tackling this problem is immense and requires a wide range of innovative solutions drawn from an equally wide range of technology discipline areas. The proposed research program is divided into three work packages (WPs): (1) Environment, Migration and Risk; (2) Decommissioning, the Historic Legacy and Site Termination; and (3) Materials - Design, Development and Performance.WP 1: Environment, Migration and RiskCleaning up contaminated land is a substantial component of nuclear site restoration. The range of radioactive contaminants present, and the potential for mixed contamination, represents a major challenge. In particular, the potential for migration of soluble and colloidal species in the subsurface is a key uncertainty in defining site end points. Currently, most cleanup is expected to be through invasive technologies; hence, we will explore more cost-effective in situ technologies such as barrier treatment systems. Many of the uncertainties and technical challenges associated with geological disposal of immobilised radioactive wastes are critically dependent on the rate of release from the engineered facility, and on the subsequent behaviour of the radionuclides in the disturbed zone and the far field. Work Package 2: Decommissioning, the Historic Legacy and Site TerminationHeterogeneous wastes present in fuel storage and handling facilities are a key target of the consortium. These wastes comprise irradiated fuel, contaminated materials and corrosion products. Total volumes and compositions (both chemical and radioactive) are poorly known, although there are believed to be several hundred m3 in each of the main storage ponds. Improved and accurate characterisation is therefore a priority, and novel technologies for retrieval and treatment are proposed here. In addition, historical activities have created small volumes of orphan wastes for which no clear management route exists; their diversity requires new and versatile treatment methods which will be developed in this programme. We also focus on the quantification of radionuclide inventories, contaminant transport through engineered pathways and waste retrieval as areas where we can make a further contribution.Work Package 3: Materials- Design, Development and PerformanceGeological disposal has been accepted by Government as the best available approach for the long term management of UK radioactive wastes, supported by a robust programme of interim storage . The focus of research in this WP is therefore to address key knowledge gaps in the conditioning, storage and disposal of wastes in order to underpin future decision making in waste management. Research is based on three key themes, aimed at: 1) understanding the effects of radiation and radiolysis on the stability of nuclear ceramics during interim storage; 2) understanding the corrosion mechanisms of spent nuclear fuels, steel packaging and HLW glasses under conditions of storage and disposal; 3) development of new materials and processing routes with the flexibility to immobilise a spectrum of wastes, including fuel debris and graphite, in a form suitable for storage and disposal. A further aspect of this WP will be development of new synthetic routes to advanced inert matrix fuels.