The U. S. Naval Civil Engineering Laboratory made a study of the problem of 
locating, handling, placing, cooling, and maintaining an unattended nuclear power 
plant on the floor of the deep ocean.!© One of the problems considered was whether 
or not fouling would be encountered at great depths, and whether it would affect the 
operation of a reactor. From the information obtained about marine growth on the 
STU I-1 materials, it is envisioned that the finned plates for heat rejection mounted 
on a reactor unit placed at this particular test site could be completely covered by 
hydroid growths after prolonged submergence especially over an area of the plates 
where optimum temperature exists for the attachment and growth of hydroids. Ina 
study !7 to control marine fouling growth in pipe systems by treatment with hot water, 
water temperatures above 42°C were found to be effective. Deep-sea hydroids and 
other fouling organisms could probably be discouraged from growing on finned plates 
if the temperature of the plates was kept above 42°C. 
FINDINGS 
1. There is considerable biological activity occurring in the sediment at 
Test Site I. 
2. Marine fouling organisms such as bryozoa, tube worms, and glass sponges 
were found on rock samples collected near Test Site | in 6,000 feet of water. 
3. Marine animals such as hydroids, sea anemones, annelid worms, and small 
white starfish were found on polypropylene and on nylon ropes used in the STU 
complex. 
4, Hydroid growths in trace to heavy amounts were present on all the test 
specimens placed on the STU. Species of tube worms, limpets, and pectens were 
the other marine animals found attached to metals, plastics, and on coated test speci- 
mens. Typical fouling organisms such as bryozoa and barnacles were not found on 
these panels. 
5. Marine microorganisms were responsible for the deterioration of (a) cotton 
and Manila rope specimens, (b) jute fibers (burlap coated with coal tar), and (c) vinyl 
plastic tube (NCEL No. 15). 
6. Two species of marine borers were found in wood specimens and have been 
identified as Xylophaga washingtona Bartsch, and Xylophaga duplicata Knudsen. The 
borers were responsible for the deterioration of 
(a) Pine, fir, and greenheart wood. Some of the tunnels made by the borers 
through pine wood measured about 3/4 inch in diameter. Both of the borer 
species were found in pine wood; however, only one specie (Xylophaga 
duplicata) was found in greenheart wood, 
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