Evening star. [volume] (Washington, D.C.) 1854-1972, 1954-01-17
First NucIeor-P Powered Sub
To Be Launched on Thursday
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summer when the submersible
heads out into the river for the
operational trial--the first test
of the practical use of atomic
power
Sailing Day Crucial.
Not until the reactor which
drives their revolutionary brain
child has passed muSter-not un-
til then will these men feel free
to accept the Nays traditional
words of praise: well done"
Between next weeks ceremony
and sailing day, there is much
to do. Nautilus is ready to float
but not submerge. Before she is
ready for sea her fltting-out
must be completed. The peri
scope must be installed and the
crews quarters completed. install
lation of auxiliary power systems
and of miles of electrical wiring
must be taken care Of. Most i'm
portant, there will be more work
on the reactor system. for the
ship is not yet able to move
under her own power.
Millions of words have been
written about Nautilus. In
open, unclassified and unofficial
sources, it has been pointed out
that her exceptionally thick skin
will allow her to dive deeper
than any previous submarine "a
German U-boat submerged to
700 feet during World War ID;
that her best underwater speed
will range from IS to 80 knots or
: more; that she can cruise at top
speed underwater for $4,000
miles; circle the globe many
times without refueling and, be-
cause the puclear reactor does
not require oxygen to operate, as
do combustion engines. she can
remain submerged indefinitely
for as long as the crew can en-
dure.
New Hull Design.
Nautilus differs from the
World War II submarine, which
could do none of the above, in
two major respects: In he's
method of propulsion and in her
hull design.
The atomic reactor which
powers the ship. in on-technical
terms, works this way: It has
as its core. a few pounds Of
Uranium 235. which is fisSion-
able. that is. its atoms can be
split. zone gram of uranium is
equivalent as power producer
to 3 tons of coal. There are
454.6 grams to the pound.)
Control rods of metal called
hafnium, which readily abSorbs
neutronS and therefore can
slow down or halt the flssion
process. are introduced into the
reactor. When these are pulled
out. fisSion starts.
To get under way, the skipper
orders the control rods in the
reactor withdrawn by mechani-
cal means. In the resulting ifs
sion. tremendous heat is pro-
duced. The. structural part of
the reactor. which is made of
chromium, a comparatively light
metal with high heat-resisting
properties and which does not
absorb neutror1s, contains the
heat.
Steam Runs Turbines.
At the same time, fresh water
Is pumped through the reactor,
at, high pressure to prevent
its turning to steam. This
water, referred to as coolant.
carries away the heat through
tubes leading to a boiler or heat
exchanger." This water is radio
active. Another supply of water
is pumped in from the other
side of the exchanger and is
turned to steam by the heat of
the reactor water. This steam,
which is not radioactive (the
waters do not come into direct
contact with each other, is
directed to the turbines. When
it strikes the blades Of these
turbines, the latter start to
spin, operating reduction gear
which rotates the propeller
shafts and propellers to drive
the ship.
The hot radioactive water,
meanwhile, passes through the
heat exchanger and is pumped
back through the reactor to
start the process again. The
other water, which had been
turned to steam, is condensed
and pumped back to the ex-
changer. to repeat it's own cycle.
A reactor, it can be seen, is
something like an ordinary
boiler, with this difference: The
heat starts from the inside and
moves outward. In a boiler. there
are tubes full of water and a
fire around them; the heat
transmittal is from the outside
to the inside. In the reactor. the
uranium rods on the inside gen.
crate enough heat to turn water
on the outside into steam.
Shielded by Lead.
A thick lead shield surrounds
the reactor. the piping leading
to the heat exchanger from the
reactor and the heat exchanger
itself to protect the crew from
radiation. This shielding is so
effective that the average crew
member will be exposed to no