456 



INTERACTION OF RADIONUCLIDES WITH SEDIMENTS AS A GUIDE TO THE FATE OF 

 RADIOCHEMICAL WASTES DISPOSED OF IN THE SEA 



This study is designed to provide a scientific basis for predicting the fate of 

 radionuclides in the marine environment, whether implanted in the sea floor (high- 

 level wastes), deposited on the seabed (low-level wastes) or released accidentally. The 

 project is funded jointly by NOAA's Office of Marine Pollution Assessment and the 

 Office of Sea Grant. The research will be conducted by Woods Hole Oceanographic 

 Institution. 



The project has two objectives: (1) to characterize the physical and chemcial 

 factors which may affect the interaction of marine sediments with both global 

 fallout and emplaced radioactive waste constituents; and (2) to delineate the process- 

 es and sedimentary characteristics which may influence or govern the transport of 

 these waste constituents within the sediments and between the sediments and the 

 overlying seawater. 



DEEPWATER SEDIMENT PORE PRESSURE PROBE (PIEZOMETER) SYSTEM 



The NOAA Marine Geotechnical Program has developed with the DOE-sponsored 

 Sandia Seabed Disposal Program plans for the design and fabrication of a deepwater 

 piezometer system to measure long-term changes in pore water pressure and sea- 

 floor stability in sediments at seabed disposal study sites. Piezometers are used to 

 measure the change of pressure of a material subject to water pressure. The system 

 will be used in Sandia experiments in Fiscal Year 1981. 



These cooperative NOAA-DOE programs should do much to further the investiga- 

 tion of disposal of high-level radioactive wastes within the seabed in a safe, environ- 

 mentally acceptable manner. At this point we know relatively little about many 

 aspects of seabed disposal, but these projects and others will begin to provide a basis 

 for making decisions about ocean disposal of high-level waste. 



OCEAN DISPOSAL OF LOW-LEVEL NUCLEAR WASTE 



I would like now to comment briefly on the low-level radioactive waste at existing 

 disposal sites off the U.S. continental shelf. Over the past decade, NOAA pollution 

 research and monitoring priorites have been directed, based on the best available 

 scientific opinion, toward those pollutants entering the marine environment that 

 posed the most significant threat to human health, living resources, and environ- 

 mental quality. Because the evidence so far indicates that radionuclides pose a 

 lesser threat than other pollutants, NOAA has not placed a high priority on re- 

 search concerning low-level nuclear wastes. I would like to summarize for you the 

 scientific evidence which led to that management decision. 



In 1971, the National Academy of Sciences (NAS) concluded that in terms of 

 ecological effects, the consensus of the scientific literature was that radionuclides 

 are not likely to be significantly deleterious in populations of marine organisms at 

 the dose rates for the most contaminated environments. The NAS also concluded 

 that there was no evidence that past ocean disposal of low-level waste has jeopard- 

 ized humans or any marine species. 



In 1978, a workshop of scientific experts met in Estes Park, Colorado, at the 

 request of NOAA, to review the status of our scienific knowledge on all ocean 

 pollution and to recommend areas where further study was necessary. These ex- 

 perts concluded that to date, no impacts on human health have been documented 

 from the ocean disposal of radionuclides and no effects harmful to marine organ- 

 isms are known, even at the sites of large discharges. The workshop did recommend, 

 however, that existing low-level radioactive waste dump sites should be watched for 

 leakage of radionuclides to test the validity of present data about retention of 

 disposed materials in sediments, and to provide a basis for the selection of future 

 disposal areas for low-level radioactive wastes. 



In 1979, NOAA issued the first five-year federal plan for ocean pollution research, 

 development, and monitoring under the National Ocean Pollution Planning Act of 

 1978. The plan, developed in cooperation with ten agencies, evaluated the full range 

 of ocean pollution problems, assigned priorities to research needs, and identified 

 high priority unmet needs. The monitoring of existing radioactive waste dump sites 

 was considered to be a medium to high priority information need. A need was 

 perceived primarily for assessment of residual radionuclide abundance and recovery 

 rates in order to evaluate future requests for ocean disposal of low-level wastes. 



Given this backdrop of scientific opinion on the relative threat posed to human 

 health and living marine resources and the limited amount of ocean pollution 

 research funding available, NOASA has not assigned a high priority to monitoring 

 radionuclides at existing dump sites. Instead, NOAA's pollution research and moni- 

 toring have focused on those areas where there is a strong scientific consensus as to 



