Advanced Waste Management Strategies for High Dose Spent Adsorbents

2011年3月11日，东日本大地震引发了毁灭性的海啸，导致至少19，000人丧生，并导致福岛Dai-ici现场的三个沸水反应堆（1-3号机组）部分熔化。在福岛Dai-ici核电站的稳定、恢复和退役计划中，一项关键技术需要是对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进行净化。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，这些设施产生各种高放射性和可分散的“高剂量废吸附剂”。关键问题是由吸附材料内的水的辐射诱导降解产生氢，这造成爆炸危险。该项目的总体目标是提高高剂量废吸附剂的被动安全性，以确保按照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，在工程设施中长期近地表储存和/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，颗粒状的和可分散的材料转化为化学和物理稳定的固定的整体形式，消除制氢的关键危险。本项目中开发的方法将满足国际退役和民用核能方案的共同需要，其中无机离子交换材料得到普遍应用。特别是，该研究将提供一种处理塞拉菲尔德场地上大量斜发沸石废物（归类为中级废物）的方法，目前还没有公认的处理方法。

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.