THE LONDON CONVENTION:.................
Since the Convention for the Prevention of Marine Pollution by Dumping of Wastes and Other Matter (referred to as the London Dumping Convention, or LDC) came into force in 1975, the dumping of waste has been regulated on a global scale. The LDC prohibits,inter alia, the dumping of HLW and requires that LLW be dumped only after a special permit has been issued. At the seventh consultative meeting (1983) of the contracting parties to the LDC, an amendment to these annexes was proposed to prohibit the dumping of allradioactive waste at sea. A resolution was adopted calling for suspension of all dumping pending a review of the scientific basis for sea dumping of radioactive wastes. In 1984, an independent panel of experts reviewed the scientific and technical considerations relevant to the proposed amendment. Their conclusion, presented at the LDC eighth consultative meeting (1985), stated that "no scientific or technical grounds could be found to treat the option of sea dumping differently from other available options when applying internationally accepted principles of radiation protection to radioactive waste disposal".In 1986, as a result of the continuous improvement of the impact assessment methodology, the IAEA presented its third version of the definition of HLW unsuitable for dumping at sea and its recommendations for the control of low-level packaged waste dumpingoperations.* Despite this new information, the LDC tenth consultative meeting (1986) agreed to establish an intergovernmental panel of experts to consider the wider political, legal, economic, and social aspects of sea dumping of LLW. The moratorium was extended pending the results of these new studies. At the same time, the IAEA was requested to devise contracting parties specifically with respect to outstanding scientific andtechnical issues.
Comparative risk studies:...........Many chemicals, some of which have been identified as carcinogens for man, are present in the marine environment as a result of the disposal of wastes from various industrial activities. In contrast to the extensive knowledge of man's exposure to ionizing radiation from all type of marine sources, the impact on human populations of non-radioactive chemicals in the oceans is not well known. In order to fill this gap a group of expertshave been convened under IAEA auspices to compare the risks estimated to result from the dumping at sea of radioactive wastes with those from other uses, applications, disposals, and disseminations of potentially hazardous substances. In 1986, the IAEA offered guidance on an approach for comparison of land-based disposal options with seadumping and the costs and risks associated with these options. Optimizing a waste management system, involves the review of a series of parameters specific tothe waste characteristics, the site environment, and available resources combined with national, social, and political factors. Currently, on behalf of the LDC, the IAEA is undertaking a review of the published studies dealing with comparative environmental and safety assessments of various disposal options for different types of solid LLW. Toward an inventory of radioactive waste dumped and released into the sea On several occasions, the LDC has requested the Agency to develop an inventory of radioactive wastes entering the marine environment from all sources. To date a provisional computerized database with information on the date, location, depth, quantity, weight, and type of containers, as well as the quantities of dumped radionuclides, has been established. Consideration is being given to including information on controlled authorized liquid releases from nuclear facilities into the coastal waters in the inventory. The rationale for the inventory is to establish aninformation base which can provide more accurate data for assessing the impact of radioactive waste dumping operations in the sea. Such an inventory will also serveas a deterrent against disposal of more waste coming from various countries than recommended in a single oceanic basin. Seabed disposal The deep sea floor is one of the most stable and predictable geologic formations on earth and has therefore been considered as a potential alternative solution to deep geological disposal of HLW on land. If a seabed disposal option was selected, packaged HLW could be embedded in the sediment using penetrators or drilling techniques. The packages would contain the wastes for500 to 1000 years after emplacement. Long-term containment, for tens of thousands of years, would be provided by the barrier properties of the sediment. In 1984, the contracting parties agreed that the LDC consultative meeting was the appropriate forum to address the scientific and legal issues of the HLW seabed disposal. It was also agreed that no HLW disposal into the seabed should take place until it is proved to be technically and environmentally acceptable, including a determination that such wastes can be effectively isolated from man and the marine environment. In 1988, the NEA/OECD Seabed Working Group concluded that sub-seabed burial of HLW was technically feasible, but added that its long-term safety assessment required further research to reduce the uncertainties before the option is used.
Further reading............ http://www.cbrneportal.com/the-disposal-of-nuclear-waste-into-the-worlds-oceans/