-d. Construction To build either plant, large 
sections must be preassembled on shore. Modules 
weighing up to 1,000 tons would be transplanted 
on barges, sunk in place, and assembled under- 
water by methods similar to those developed for 
vehicular tunnel construction. 
e. Storm Threat There are no technological or 
physical impossibilities in constructing a plant 
having its generating equipment on the surface. 
However, the frequency of storms on the Atlantic 
Coast cannot be ignored, and provision must be 
made to evacuate and secure the station before 
large storms. The surface structure and equipment 
is subject to the full force of the storm. The 
structure could be made sturdy to withstand a 
500-year storm,°® but this is not economically 
feasible. 
The plant having generating equipment on the 
ocean floor is protected from storms, as the largest 
storms would produce only minor disturbances at 
150 to 200 foot depths. However, transporting 
manpower to and from the sea floor station, 
performing maintenance on the large turbines and 
generators, and providing personnel quarters and 
subsistence would increase operating costs. 
f. Transmission Extra-high voltage cables in oil- 
filled pipes could be laid on the ocean floor to a 
distribution net ashore or to undersea sites. How- 
ever, the maximum length of cable would be about 
20 miles due to power losses; relay stations for 
longer distances add considerably to the cost and 
difficulties. Both designs require a site at 200 feet; 
the mean distance of such sites from the U.S. 
Atlantic Coast is 50 miles. A 50-mile line with two 
relays could be a very costly venture—an excessive 
amount for power transmission. 
g. Embedded and On-Bottom Plants On _ the 
Atlantic Coast or Gulf Coast distance between the 
power plant and the shore must be reduced. Five 
miles from the Atlantic Coast the depth averages 
about 60 feet. The reactor could be placed at the 
required depth by embedding in the ocean floor. A 
hole 100 feet deep in the sea floor would provide a 
total depth of 160 feet. The sea floor of the ULS. 
Atlantic Continental Shelf is basically alluvial 
ing 500-year storm is the most severe storm statisti- 
cally predicted to occur in such a period. 
sediments, making excavation relatively inexpen- 
sive. 
Embedded reactor design was studied recently 
by the Oak Ridge National Laboratory and the 
Bechtel Corporation. They proposed an artificial 
island one-half mile from shore in which a caisson- 
enclosed reactor is embedded to a depth of 130 
feet. Total costs estimated by adding cost of 
building an artificial island and the enclosing 
caisson plus the cost of a conventional plant 
ashore appear unsatisfactory. 
A plant built for the ocean bottom is similar 
except that the compact and efficient high temper- 
ature gaseous reactor is placed in an excavation at 
a depth of 150 to 200 feet. (The excavation could 
be made by nuclear explosion like those of Atomic 
Energy Commission Plowshare projects.) No cais- 
son would be required, and water and sea floor 
sediments would serve as the radiation shield. The 
turbine-generator system on the sea bottom at 50 
to 60 feet would be filled with air at ambient 
pressure. At this depth, decompression is minimal, 
simplifying maintenance problems. 
h. Costs A rough cost comparison with an 
onshore site can be formulated, although this is 
not possible if an onshore site is not available. The 
first major savings are in land cost and construc- 
tion of the radiation shield. 
Large units (500 to 1,000 tons) of the sub- 
merged nuclear power plant would be built on 
shore, floated to the site, and sunk in place, 
making the cost of the turbine-generator equip- 
ment the same as for an onshore plant. The cost of 
excavation on the U.S. Atlantic Shelf could be less 
than building a suitable island to support the 
plant. The other large item of expense is the 
structure containing the turbine-generator system. 
2. Future Needs 
With the continued need of nuclear power 
plants to supply economical power, offshore sub- 
merged plants must be given serious consideration. 
The foregoing example of a submerged nuclear 
power plant illustrates the feasibility of such a 
project. Added advantages which improve eco- 
nomic considerations are use of the ocean as a heat 
sink, improving ecological situations, and avoiding 
thermal pollution problems ashore. An artist’s 
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