Advanced Waste Management Strategies for High Dose Spent Adsorbents

2011年3月11日的日本东部大地震引发了毁灭性的海啸，造成至少19,000人丧生，福岛第一核电站(1-3号机组)的三个沸水反应堆部分熔毁。在福岛第一核电站的稳定、恢复和退役计划中，需要的一项关键技术是净化用于冷却受损反应堆堆芯的水和渗入受损反应堆建筑的地下水。这是通过使用商业无机离子交换材料在几个专门建造的设施中剥离放射性核素污染物来实现的，这些设施产生了各种高放射性和可分散的“高剂量耗尽吸附剂”。最令人担忧的是，辐射导致吸附材料内的水降解产生氢气，这构成了爆炸危险。该项目的总体目标是根据原子能机构关于放射性废物储存和处置前管理的安全标准，提高高剂量废吸附剂的被动安全性，以确保在工程设施中长时间的近地表储存和/或处置。为了实现这一目标，我们将开发新的热处理方法，将湿的、颗粒状和可分散的材料转化为化学和物理稳定的不可移动的整体形式，消除制氢的关键危险。该项目制定的办法将满足国际退役和民用核能方案的共同需要，在这些方案中，无机离子交换材料得到普遍应用。特别是，这项研究将提供一条路线来处理塞莱菲尔德遗址上存在的大量斜发沸石废物(被归类为中级废物)，目前还没有可接受的处理路线。

The Great East Japan Earthquake, on 11 March 2011, triggered a devastating tsunami, leading to the loss of at least 19,000 lives and partial melt down of three boiling water reactors at the Fukushima Dai-ici site (Units 1-3). A key technology need in the site stabilisation, recovery and decommissioning programme at the Fukushima Dai-ici site is the decontamination of water used to cool the damaged reactor cores and ground water infiltrating the damaged reactor buildings. This is achieved by use of commercial inorganic ion exchange materials to strip the radionuclide contaminants in several purpose built facilities, which yield a variety of highly radioactive and dispersible "High Dose Spent Adsorbents". Of key concern is the production of hydrogen from radiation induced degradation of water within the adsorbent material, which poses an explosive hazard. The overarching aim of this project is to improve the passive safety of the high dose spent adsorbents to assure prolonged near surface storage and / or disposal in an engineered facility, in accordance with IAEA Safety Standards for the storage and pre-disposal management of radioactive wastes. To achieve this goal, we will develop novel thermal treatment approaches to transform the wet, granular, and dispersible material into an immobile monolithic form which is chemically and physically stable, eliminating the key hazard of hydrogen production. The approaches developed in this project will address a common need in international decommissioning and civil nuclear energy programmes, in which inorganic ion exchange materials find common application. In particular, the research will provide a route to treat a substantial volume of clinoptilolite waste present on the Sellafield site (classed as intermediate level waste) for which there is no currently accepted treatment route.