The conference ‘Disposal of radioactive wastes in seabed sediments’ was organized by the Society for Underwater Technology to renew the potential of certain seabed sediments to provide a long-term containment for radioactive wastes The conference marked the end of an extensive international research programme that addressed the feasibility of deep ocean disposal of heat-generating radoactive waste (HGW), and its objectives were to assess
what has been learned about the properties and nature of the sediments of the deep ocean,
the merits and dements of the conceptual techniques that have been developed to dispose of waste, and
whether what has been learned about deep ocean disposal has any relevance to other areas of marine science.
This chapter introduces the subject matter of the conference in the framework of the international research programme and discusses what has been learned about the role of the sediment barrier
Certain areas of the deep ocean offer a number of potential advantages for the containment of hazardous wastes, such as low levels of biological activity, no known mineral or hydrocarbon resources, stability on a geological time-scale and emoteness from humanity. In addition, because of their ion sorbing capability and immobile pore waters, the sediments at these areas may provide an effective barrier for the containment of the long-lived rahonuclides present in high-level or heat-generating radioactive waste (HGW) on time-scales that extend far beyond those that can be provided by any engineered containment.
To assess these potential advantages and to determine whether suitable areas of the deep ocean could be identified, the Seabed Working Group (SWG) was set up in 1976 by the Nuclear Energy Agency (NEA) to co-ordinate research at an international level, this work involved a multi-disciplinary study of the sediments of the deep ocean in unprecedented detail Major technological advances in both laboratory and in situ testing have been necessary to study conceptual disposal techniques and to measure the required sediment parameters Moreover, the development of innovative theoretical models has been encouraged by the need to tackle new problems, such as the behaviour of a fast moving object impacting soft soils, and the effects of radiogenic heating on seabed sediments.
Many of the considerations relevant to ocean disposal of HGW may also be pertinent to the offshore disposal of low- and intermediate-level waste (LLW and ILW), and to the disposal of other hazardous or toxic wastes, for example, an offshore repository is one option that is being considered by the UK's Nuclear Industry Radioactive Waste Executive (NIREX) for the disposal of LLW and ILW.
The conference ‘Disposal of radioactive wastes in seabed sediments’ was organized by the Society for Underwater Technology to review the potential of certain seabed sediments to provide a long-term containment for radioactive wastes.