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

英国民用核计划过去60年的遗留废物处理和处置以及退役和场地修复，保守估计英国纳税人的成本为700亿英镑。在解决这一问题时必须解决的问题的多样性是巨大的，需要从同样广泛的技术学科领域中得出广泛的创新解决方案。拟议的研究计划分为三个工作包（WP）：（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，迁移和风险清理污染土地是核场地恢复的重要组成部分。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，在地下的可溶性和胶体物种的迁移的潜力是一个关键的不确定性，在定义站点的终点。目前，大多数清理预计将通过侵入性技术;因此，我们将探索更具成本效益的原位技术，如屏障处理系统。与固定放射性废物的地质处置相关的许多不确定性和技术挑战主要取决于工程设施的释放速率，以及放射性核素在扰动区和远场的后续行为。工作包2：退役、历史遗产和场地终止燃料储存和处理设施中存在的异质废物是该财团的一个关键目标。这些废物包括辐照燃料、污染材料和腐蚀产物。总体积和成分（化学和放射性）知之甚少，但据信每个主要储存池中有数百立方米。因此，改进和准确的表征是一个优先事项，并提出了新的技术检索和治疗。此外，历史活动产生了少量无主废物，对此没有明确的管理途径;其多样性要求本方案将开发新的通用处理方法。我们还专注于放射性核素库存的量化，通过工程路径和废物回收的污染物运输，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方法，并得到了强大的临时存储计划的支持。因此，本工作方案的研究重点是解决废物调节、储存和处置方面的关键知识差距，以支持未来的废物管理决策。研究工作围绕三个关键主题展开，目的是：1）了解辐射和辐解对核陶瓷在临时储存期间稳定性的影响; 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）开发新材料和加工路线，灵活地固定一系列废物，包括燃料碎片和石墨，以适于储存和处理的形式。该WP的另一个方面将是开发先进惰性基质燃料的新合成路线。

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.