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Finally, a document prepared for review which identifies wheth- 

 er the program at this point is technically and environmentally 

 feasible. If it is not found feasible the program is stopped. 



The timeframe for this gate is 1986-87, funds permitting. 



On the next figure you can see the subsections of the program. 

 They are: Site selection, environmental studies, multiple barrier 

 quantification, waste emplacement, transportation, risk/safety 

 analyses, and social scientific. Each of the sections is defined in 

 detail in the program plan. 



I would now like to address some of the research done to date. 



One of the most important problems for the disposal of high-level 

 wastes is the effects of heat. Figure 9 shows the temperature pro- 

 file of an emplaced canister — 50m depth — as a function of time. At 

 the canister's surface the temperature is very high for this calcula- 

 tion, 250° C, but it decays very, very rapidly. In less than 10 years 

 it has passed through the peak temperature and starting to de- 

 crease. This means that we can test in real time for a lot of the 

 thermal responses of the geologic formations that are critical to the 

 program. 



Our in situ heat transfer experiment (ISHTE), which is the 

 equivalent of an underwater Moon lander, is being developed to 

 verify the thermal predictions and models that we now making. 



The ISHTE experiment will be on the floor of the ocean for 

 approximately 1 year and will measure temperatures at the canis- 

 ter interface and at locations radially out from the canister, the 

 can sediment interface is expected to reach approximately 300° C. 



To develop the best canisters we have thus far measured corro- 

 sion rates of typical materials in the marine environment. The best 

 material found is ticode-12, a titanium, copper, nickel alloy (figure 

 11). 



Figure 12 shows that, for example, if you want a canister that 

 lasts 1 year, ticode is not the choice, from a cost standpoint. How- 

 ever, if you want a canister that lasts 300 years of longer ticode-12 

 is a very, very acceptable material as far as cost is concerned. 



Figure 8 shows two views of the results of the calculations that 

 have been made for radionuclide migration. On the left half of the 

 figure the little black spot is the canister. These calculations as- 

 sumed that the plutonium was released instantaneously after the 

 canister was put into the sediments and the hole was acceptedly 

 plugged with sediment. The figure there represents a snapshot of 

 the radionuclide concentration around the can, 100,000 years into 

 the future. The plutonium has moved approximately four canister 

 lengths during the period of time and has decayed to essentially 

 background. There is one problem, however to date we have only 

 developed an understanding of the response of positively charged 

 radionuclides. We have yet to assess the problems dealing with the 

 negatively charge radionuclides. Positive ions, it seems, stick very 

 well to the sediments. Negative ions may not stick at all. 



Future nuclide transport research will address the movement of 

 the negative charged nuclides through the red clay sediments. 



Another area that we have not yet addressed and remains un- 

 known concerns the plastic properties of the sediment. Since the 

 sediments are plastic they are relatively immune to mechanical 

 things like earthquakes, impacts and earth fracture — there is no 



