The dilution caused by the heat emission of the wastes depends 
a great deal upon the density gradient of the ocean at the site. 
The density gradient near the ocean bottom is not accurately known; 
oceanographers have been trying to measure it for years. The difficulty 
lies in the fact that thermometers cannot be placed at precise depths 
measured from the ha 
Sampling problems: It is very difficult to sample at short distances 
above the bottom. The technique of handling instruments at precise 
distances above the bottom is not yet sufficiently well developed 
to proceed with bottom layer Peres a creitineh the Lamont 
group has worked out a system whereby samples can be taken near the 
bottom in conjunction with their core sampling device. A mechanism 
on the corer trips the water sampler or electrical thermometer attached 
to the device. By this procedure the water is sampled at 30 feet 
from the bottom. It would be possible to approach closer to the bottom 
but it would be more difficult to get a core at the same saa 
Radioactivity readings may be taken instantaneously by sending 
down a sensing instrument. This procedure should be feasible if the 
concentration is high enough. The limiting level is about 1077 micro- 
curlies per Stes However, if the instrument is used for continuous 
underwater measurements it will absorb radioactivity and this will 
result in continued readings even after the activity has eae 
This trouble can be avoided by leaving the instrument down only long 
enough for the ha el 
Adaptable Instrument: There are instruments similar to those 
used for mine hole logging under water pressure which might be extended 
"67- 
