The _ATOM_ and the _OCEAN_


                         by E. W. Seabrook Hull


                     U.S. ATOMIC ENERGY COMMISSION
                   Division of Technical Information
                    _Understanding the Atom Series_




                   The Understanding the Atom Series


Nuclear energy is playing a vital role in the life of every man, woman,
and child in the United States today. In the years ahead it will affect
increasingly all the peoples of the earth. It is essential that all
Americans gain an understanding of this vital force if they are to
discharge thoughtfully their responsibilities as citizens and if they
are to realize fully the myriad benefits that nuclear energy offers
them.

The United States Atomic Energy Commission provides this booklet to help
you achieve such understanding.

                                                  {Edward J. Brunenkant}
                                          Edward J. Brunenkant, Director
                                       Division of Technical Information

  UNITED STATES ATOMIC ENERGY COMMISSION

  Dr. Glenn T. Seaborg, Chairman
  James T. Ramey
  Wilfrid E. Johnson
  Dr. Theos J. Thompson
  Dr. Clarence E. Larson




                       The _ATOM_ and the _OCEAN_


                         by E. W. Seabrook Hull




                                CONTENTS


  SEEKING ANSWERS                                                      1
      Energy for Exploration                                           3
  THE WORLD OCEAN                                                      6
      Ocean Movements                                                  7
      A Mix of Elements                                               10
      The Sea’s Interfaces                                            11
      The Sea’s Resources                                             11
  NUCLEAR ENERGY’S ROLE                                               13
      Radionuclides in the Sea                                        13
      Research Projects                                               23
      Oceanographic Instruments                                       35
      Environmental Safety Studies                                    41
      The Atom at Work in the Sea                                     42
      Ocean Engineering                                               51
      Fresh Water from Seawater                                       52
      Radiation Preservation of Seafood                               54
      Project Plowshare                                               56
      A New _Fram_                                                    56
  THE THREE-DIMENSIONAL OCEAN                                         57
  SUGGESTED REFERENCES                                                58


                 United States Atomic Energy Commission
                   Division of Technical Information
           Library of Congress Catalog Card Number: 67-62476
                                  1968

    [Illustration: uncaptioned frontispiece]




                       The _ATOM_ and the _OCEAN_


                                                  By E. W. SEABROOK HULL




                            SEEKING ANSWERS


Historians of the future will record that man almost simultaneously
unlocked the secret of atomic energy and ventured into new domains
beneath the closed doors of the world ocean, in one of the greatest
exploration endeavors of all time.

History may also show how these two efforts to benefit mankind became
closely interthreaded—how nuclear energy, in its many forms and
applications, played a major role in the efforts to explore and exploit
“the other three-quarters” of our planet, and moreover, how the very
development of a nuclear technology enforced our need to know more about
the sea around us.

Nuclear energy is a fundamental physical phenomenon, like the actions of
the wheel, the lever, or the inclined plane. Like chemical combustion or
electricity, it is but another means for men to do useful work, whether
that work be in the interests of science, commerce, recreation, or war.
To this extent, nuclear energy is universal, as applicable in the sea as
it is on land or in outer space. Wherever man goes and whatever he does,
he requires energy to get him there and energy for his work or play when
he arrives. Some of the places he now seeks to pioneer are hard to
investigate by anyone encumbered with bulky traditional energy
sources—coal, fuel oil, or storage batteries. The ocean in its full
three-dimensional scope is one of these places.

The atom is the most concentrated source of energy, and one of the most
diverse. Thus, not only are we able to do familiar things better with
nuclear energy (the nuclear-powered submarine is a dramatic example),
but we are also able to do things never before possible (such as
studying the diffusion of dissolved salts in the open ocean or extending
the useful life of seafoods through irradiation).

Nuclear energy has at last enabled us to realize the predictions of
Jules Verne’s adventure tale, _Twenty Thousand Leagues Under the Sea_,
and to build a true submarine—a craft whose submerged existence is
limited only by the physiological and psychological endurance of its
human crew. This fact in itself has added greatly to our need to learn
much more about the ocean, for the sea is an opaque and strange
environment in which the deadly game of hunt-and-be-hunted will be won
by whoever knows the ocean best.

The very fact that we have nuclear energy means we have nuclear wastes;
many of these inevitably find their way into the ocean, as all things
do. We need to know more about the watery world before we can safely
allow this inflow to continue.

    [Illustration: _In 1900 the U. S. Navy commissioned its first
    submarine, the USS_ Holland, _which was built by John P. Holland. It
    is shown in dry dock at Perth Amboy, New Jersey, in 1898._]

    [Illustration: _The USS_ Plunger, _named after an early John Holland
    submarine, which is an example of the Navy’s present fleet of
    nuclear submarines._]

In the waters of the seven seas are enough deuterium and tritium to
power tomorrow’s thermonuclear power plants[1] for millions of years.
These rare, heavy varieties of hydrogen, enormously abundant in the
vastness of the sea, comprise an energy source without limit for all
nations, which need only develop the technological ability to extract
them and put them to work.


Energy for Exploration

For this exploration, men need to put instruments, navigation beacons
(see figures on pages 46 and 47), and other devices on the deep ocean
floor, where they must operate for long periods of time unattended and
with no external source of power. Radioisotope-powered generators,
capitalizing on the energy of disintegrating radioactive atoms, are
almost the only devices capable of fulfilling these requirements.[2] Man
also wants to do productive work under the ocean, such as drilling
seafloor oil wells, mining, and salvaging for profit some of the tens of
thousands of cargoes lost at sea during thousands of years of ocean
commerce. Eventually, he even wants to farm the ocean floor.

    [Illustration: _An artist draws (using pencil and frosted plastic
    sheet) the position of objects in the wreck of a 7th century
    Byzantine ship 120 feet down in the Aegean Sea. Nuclear power will
    permit historians of the future to remain underwater for long
    periods exploring shipwrecks or old cities far below the surface._]

All these activities require energy—energy in an environment where most
sources cannot be applied. Above all, man wants to go down himself to
explore, to work, and perhaps to direct nuclear-powered robots to do
even more work. This means that small, manned, nonmilitary submersibles
will be needed—vessels whose endurance should not be limited by the
short life of traditional power sources, but should draw on the
fissioning atomic nucleus, harnessed in small reactors.[3]

To work effectively in any environment, we must first know and
understand it. This is the job of science. In the quest for knowledge
and understanding of the ocean, nuclear energy provides scientists with
better instruments to put down into the depths and wholly new techniques
for the direct study of the many oceanic processes.

For example, take the role of radioisotope tracers: For the first time,
these telltale atoms permit us to study the metabolism of tiny
plankters, the often microscopic drifting creatures of the sea that in
their incredible abundance form the base of the entire marine food
chain, including fish eaten by humans. Even fallout isotopes from
nuclear tests enable us to trace important physical oceanographic
events, such as the ponderous process known as overturning, which
transports oxygen-rich surface water to the deeps and nutrient-rich
bottom water to the surface. Radioisotope tracers also provide a tool
for studying the mechanics of littoral transport, which continually
tears down some beaches and builds up others. They also enable us to
determine if oceanic processes are likely to concentrate fallout
particles and deliver them in dangerous doses through the food chain to
our dinner tables.[4]

By using other nuclear energy technology, we are better able to
ascertain the age and composition of deep ocean sediments and the rate
at which they are deposited, how a tsunami (tidal wave) propagates
across vast distances, how tides operate in the open ocean, where the
brown shrimp of the Carolina coast go every fall, and the migration
patterns of tuna, swordfish, and other valuable food fish.

    [Illustration: _Navy men preparing for undersea research by feeding
    Tuffy, a friendly porpoise, which later carried messages for them
    during the “Man-In-The-Sea” experiment._ (_Also see photos on page
    12._)]

These are just a few of the answers we seek from the world ocean—answers
important for more productive fisheries, more accurate long-range
weather forecasting, possible control of hurricanes and typhoons,
pollution control, safer and more economical shipping, better
recreation, and numerous other matters that bear on our health,
well-being, and day-to-day lives.

On all these endeavors the ocean exerts a major influence. And in each,
atomic energy is helping assemble and interpret answers.




                            THE WORLD OCEAN


But what of this environment into which, armed with the atom, we plunge
with such enthusiasm and expectations? A portrait is in order, which
must be brief, for not all the books ever written about the sea have yet
described it fully.

The world ocean covers 70.8% of our planet. It contains 324,000,000
cubic miles of seawater. Living in it are upwards of a million different
species of plants and animals. They range from one-celled organisms that
can only be seen with a microscope to the largest creature ever to have
lived on this earth—the giant blue (or sulfur-bottom) whale, captured
specimens of which have exceeded 90 feet in length and 100 tons in
weight.

The ocean’s depth ranges from 600 feet or less above continental shelves
to more than 35,000 feet at the Marianas Trench. The mean depth is
12,451 feet. Sea bottom topography includes wide plains, the world’s
longest mountain range, steeply rising individual truncated peaks called
_guyots_ (pronounced gee-ohs), gentle slopes, narrow canyons, and
precipitous escarpments. Mountains higher than Everest rise from the
ocean floor and never pierce the surface.

    [Illustration: _Underwater mountain traced by the Woods Hole
    Oceanographic Institution echo sounder in the Caribbean area. Depth
    is determined by the time it takes the sound emitted by the
    instrument to go to the bottom and return to the surface._]


Ocean Movements

    [Illustration: _Six ships checking the Gulf Stream’s course through
    the Atlantic Ocean over a 2-week period found the variations shown
    above._]

    [Illustration: _The infrared film photograph shows the edge of the
    Gulf Stream. The visible line between the Gulf Stream, which is on
    the right, and Labrador water is made by Sargassum weed concentrated
    at the interface._]

The ocean is constantly in motion—not just in the waves and tides that
characterize its surface but in great currents that swirl between
continents, moving (among other things) great quantities of heat from
one part of the world to another. Beneath these surface currents are
others, deeply hidden, that flow as often as not in an entirely
different direction from the surface course.

These enormous “rivers”—quite unconstant, sometimes shifting, often
branching and eddying in a manner that defies explanation and
prediction—occasionally create disastrous results. One example is El
Niño, the periodic catastrophe that plagues the west coast of South
America. This coast normally is caressed by the cold, rich Humboldt
Current. Usually the Humboldt hugs the shore and extends 200 to 300
miles out to sea. It is rich in life. It fosters the largest commercial
fishery in the world and is the home of one of the mightiest game fish
on record, the black marlin. The droppings of marine birds that feed
from its waters are responsible for the fertilizer (guano) exports that
undergird the Chilean, Peruvian, and Ecuadorian economies.

Every few years, however, the Humboldt disappears. It moves out from
shore or simply sinks, and a flow of warm, exhausted surface water known
as El Niño takes its place. Simultaneously, torrential rains assault the
coast. Fishes and birds die by the millions. Commercial fisheries are
closed. The beaches reek with death. El Niño is a stark demonstration of
man’s dependence on the sea and why he must learn more about it.

There are other motions in the restless sea. The water masses are
constantly “turning over” in a cycle that may take hundreds of years,
yet is essential to bring oxygen down to the creatures of the deeps, and
nutrients (fertilizers) up from the sea floor to the surface. Here the
floating phytoplankton (the plants of the sea) build through
photosynthesis the organic material that will start the nutrient cycle
all over again. Enormous tonnages of these tiny sea plants, rather than
being rooted in the soil, are separated from solid earth by up to
several vertical miles of saltwater. Sometimes, too, there is a more
rapid surge of deep water to the surface, a process known as upwelling.

Internal waves, far below the surface, develop between water masses that
have different densities and between which there is relative motion.
These waves are much like the wind-driven waves on the surface, though
much bigger: Internal waves may have heights of 300 feet or more and be
6 miles or more in length!

    [Illustration: _A dividing cell of the diatom_ Corethron hystrix.
    _Diatoms, one-celled photosynthetic plants, are the primary
    producers of organic matter in fresh waters._]

    [Illustration: _Ocean currents feed sand from nearby beaches into
    this “sandfall”, which is about 30 feet high, in a submarine canyon
    off Baja California._]

Among other motions of the sea there are landslides, or turbidity
currents, which are great boiling mixes of mud, rock, sand, and water
rushing down submarine mountainsides at speeds of a mile a minute. They
destroy everything in their paths and spread clouds of debris over the
abyssal plains like a sandstorm, producing fanlike deposits radiating
far out from the base of the slope. And there are tsunamis, or seismic
sea waves—popularly misnamed “tidal waves”—that transmit energy from
undersea earthquakes or volcanic eruptions. At sea, these waves are only
a few inches high, but they may travel great distances at 500 miles an
hour. As they approach the shoaling waters of a coast, they are slowed
to about 30 miles an hour and build up great surface waves capable of
destroying harbor and coastal installations.


A Mix of Elements

The sea is a chemistry, too. Over 60 elements have been discovered in
measurable amounts in solution or in suspension in the ocean. Many of
these are in the form of salts, making seawater a highly efficient
electrolyte, and a most corrosive fluid. The study of corrosion and
techniques for combatting it is a continuous one in which nuclear energy
already has a principal role.

Because the sea is so much a chemistry, it is a potential source of
minerals for the world’s growing industrial appetite. All of our
magnesium and most of our bromine already are extracted directly from
seawater. Oil and sulfur are mined from the sea floor or beneath it, as
are coal (United Kingdom and Japan), iron ore (Japan), tin (Thailand and
United Kingdom), diamonds (Southwest Africa), and gold (Alaska). In the
layered sediments that cover the ocean-basin floors to depths of
thousands of feet, geologists believe there also may be found some
missing chapters of earth history.

    [Illustration: _Nodules such as these containing manganese cover
    millions of undersea acres on the ocean floor. Many nodules are rich
    in nickel, cobalt, zirconium, and copper. Metallurgists are seeking
    ways to recover the metals from these deposits._]

The ocean, by and large, is an opaque fluid through which light travels
only a few hundred feet and most other radiant energy not much more than
a few yards; yet through this same fluid, sound waves, by contrast, have
been transmitted and received over distances of many thousand miles.


The Sea’s Interfaces

What of the interfaces of the sea? Above three-quarters of the globe,
water and air are in constant contact, continually exchanging heat and
moisture. This is a major factor in the making of weather and climate.
The sea constantly feeds electricity into the atmosphere, primarily
through the electron-scrubbing action of tiny popping bubbles at the sea
surface. It also lifts tiny crystals of salt and the remains of
microscopic sea creatures into the air. Perhaps these are the nuclei on
which moisture condenses to trigger hurricanes, since it is the latent
heat of vaporization of air, made over-moist by long travel over the
tropical sea, that provides a hurricane’s energy.

Along its land edges, the sea is constantly working on the
shore—sometimes gently, sometimes violently—breaking down rock cliffs,
opening bays and harbors, closing channels and inlets, smashing
breakwaters and seawalls, and moving sand up and down and to and from
beaches.


The Sea’s Resources

In summary, then, the ocean, the largest single geographical feature of
our planet, is infinitely varied and infinitely complex. We are learning
it bears on our day-to-day living in ways we never suspected. It is the
largest resource of food for our exploding population, the largest
resource of minerals with which to support the world’s burgeoning
industries, the largest resource of energy, and, of course, it is the
largest supply of water. It is mankind’s largest dumping ground for the
wastes of cities and industries. It is the source of much pleasure and
recreation.

Men already have lived experimentally for weeks at a time on the bottom
of the ocean. Both sea floor laboratories and military bases are being
planned or, in a few cases, installed. Sea floor mining complexes are in
the conceptual design stage. It is only a matter of time before
recreational “aquotels” are built safely below the sea’s restless
surface. Private sports submarines are an actual, though costly,
reality. It is not inconceivable that in the not-too-distant future
human beings may overflow the land into complete, self-sufficient
communities below the oceans.

    [Illustration: _In 1965 the U. S. Navy conducted a 45-day experiment
    in its “Man-In-The-Sea” program in which 10 aquanauts lived and
    worked 205 feet below the surface of the sea off La Jolla,
    California. Their undersea base was Sealab II shown at her
    christening._]

    [Illustration: _Sealab II shown during final checkout before
    descent. The aquanauts conducted experimental salvage operations,
    marine research, and underwent a series of physiological and human
    performance tests._]




                         NUCLEAR ENERGY’S ROLE


The role of nuclear energy in the study, exploration, and utilization of
the world ocean is best defined by citing the specific oceanographic
interests of the U. S. Atomic Energy Commission (AEC): Development of
better instruments and devices for work and study in the ocean,
development of ever-stronger national sea power, conversion of seawater
to fresh water, possible modification of ocean boundaries, purely
scientific studies to advance knowledge, and, indirectly at least,
improving the state of oceanographic engineering. Among the
technological products of the nuclear age are radionuclides, neutron
sources and other radiation sources, radioisotope heat and electric
generators, and nuclear reactors. All these are applied to ocean-related
endeavors.

Several divisions of the AEC have important oceanic interests. These
range from pure oceanographic research to development of specific
instruments, nuclear reactors, radioisotopic power sources, and other
devices for use in or under the ocean. The AEC also conducts extensive
marine environmental studies to monitor the effects or ensure the safety
of specific projects involving nuclear energy. A statistical summary of
specific AEC programs in oceanography is shown in Table I on page 14.


Radionuclides in the Sea

Before we can follow the atom down into the sea, we must understand
something about the potentials, both good and bad, of this incursion of
one of our most advanced technologies into one of earth’s least
understood environments. This adventurous probing has ramifications for
studying both man-produced radioactivity in the sea and the ocean itself
as an uncontaminated environment.

                                 TABLE I
                  AEC OCEANOGRAPHY PROGRAM                     1968
                                                           Expenditures
                                                             Estimate
  _Research Activities_

  Division of Biology and Medicine                            $4,000,000
     Studies of uptake, concentration, distribution and
     effects of radioisotopes on marine life, of
     geochemical cycling of elements, and of geophysical
     diffusion and transport.
  Division of Research                                            25,000
     Geological dating of corals and other marine and
     terrestrial materials.
  Division of Isotopes Development                               190,000
     Radioisotope applications to devices for marine
     systems, such as current meters, analysis and
     recovery of sedimentary minerals, and underwater
     sound transmission.
  Division of Reactor Development and Technology                 197,000
     Studies of factors affecting dissolution and
     dispersal of accidentally released radionuclides, and
     site evaluations.
  Division of Space Nuclear Systems                              275,000
     Nuclear power sources for aerospace applications.
  Division of Military Applications                              850,000
     Ocean environmental observation and prediction.
                                _Total—Research Activities_    5,537,000

  _Engineering Activities_

  Division of Reactor Development and Technology               5,900,000
     Radioisotope and reactor power development.
  Division of Naval Reactors                                   1,320,000
     Deep submergence research vehicle.
                            _Total —Engineering Activities_    7,220,000
                       _Total—ABC Oceanographic Activities_   12,757,000

Radionuclides (radioactive atoms) can find their way into the sea from
natural radiation sources or from nuclear energy operations undertaken
by the United States and other countries since 1945. Specific man-made
sources in the past may have included nuclear weapons tested in the
atmosphere and under water, the cooling water and wastes of nuclear
reactors, laboratories and nuclear-powered ships, containers of
radioactive waste disposed of at sea[5], radioisotope energy devices,
and intentional injection of radioisotope tracers for scientific
research. In the future, they may also include reentry from space of
upper-stage nuclear rockets or satellite-borne nuclear energy sources.

    [Illustration: _The Nansen bottle, shown being attached to a
    hydrographic wire, is one of the standard tools of oceanology. When
    a bottle reaches a desired depth, a sliding weight tips it upside
    down to collect seawater samples. Thermometers on the sides of the
    bottles record temperature. The device was designed by the Norwegian
    oceanographer and explorer, Fridtjof Nansen._ (_See photo on
    page 56._)]

In order to evaluate the effects of these materials in the ocean
environment, it is necessary to know many things. Just how much
radiation is introduced? In what form? Where geographically? How are
these radionuclides dispersed or concentrated physically, chemically,
biologically, and geologically? What is the net result in each case now,
and what will it be many years hence?

These questions are not answered easily. There is, as yet, no
satisfactory laboratory substitute for the open ocean. Research for the
most part must be conducted at sea, where tests and measurements are
difficult at best, and where results therefore are often suspect.
Further, if we are to study the effects of man-induced changes in a
natural environment, it would have been advantageous to have known the
nature of that environment before the changes were introduced—which, by
and large, in the case of the ocean we do not. So we must start with a
contaminated environment and try to separate what we have put there
ourselves from what would have been there anyway. It isn’t an easy task
to make the physical and biological observations that will make this
distinction.

   Table II CONCENTRATION AND AMOUNTS OF 42 OF THE ELEMENTS IN SEAWATER
    Element     Concentration   Amount of element in    Total amount in
                   (mg/l)       seawater (tons mile³)  the oceans (tons)

  Chlorine     19,000.0        89.5 × 10⁶                    29.3 × 10¹⁵
  Sodium       10,500.0        49.5 x-10⁶                    16.3 × 10¹⁵
  Magnesium    1,350.0         6.4 × 10⁶                      2.1 × 10¹⁵
  Sulphur      885.0           4.2 × 10⁶                      1.4 × 10¹⁵
  Calcium      400.0           1.9 × 10⁶                      0.6 × 10¹⁵
  Potassium    380.0           1.8 × 10⁶                      0.6 × 10¹⁵
  Bromine      65.0            306,000                        0.1 × 10¹⁵
  Carbon       28.0            132,000                       0.04 × 10¹⁵
  Strontium    8.0             38,000                       12,000 × 10⁹
  Boron        4.6             23,000                        7,100 × 10⁹
  Silicon      3.0             14,000                        4,700 × 10⁹
  Lithium      0.17            800                             260 × 10⁹
  Rubidium     0.12            570                             190 × 10⁹
  Phosphorus   0.07            330                             110 × 10⁹
  Iodine       0.06            280                              93 × 10⁹
  Barium       0.03            140                              47 × 10⁹
  Indium       0.02            94                               31 × 10⁹
  Zinc         0.01            47                               16 × 10⁹
  Iron         0.01            47                               16 × 10⁹
  Aluminum     0.01            47                               16 × 10⁹
  Molybdenum   0.01            47                               16 × 10⁹
  Selenium     0.004           19                                6 × 10⁹
  Tin          0.003           14                                5 × 10⁹
  Copper       0.003           14                                5 × 10⁹
  Arsenic      0.003           14                                5 × 10⁹
  Uranium      0.003           14                                5 × 10⁹
  Nickel       0.002           9                                 3 × 10⁹
  Vanadium     0.002           9                                 3 × 10⁹
  Manganese    0.002           9                                 3 × 10⁹
  Antimony     0.0005          2                               0.8 × 10⁹
  Cobalt       0.0005          2                               0.8 × 10⁹
  Caesium      0.0005          2                               0.8 × 10⁹
  Cerium       0.0004          2                               0.6 × 10⁹
  Silver       0.0003          1                                 5 × 10⁸
  Cadmium      0.0001          0.5                             150 × 10⁶
  Tungsten     0.0001          0.5                             150 × 10⁶
  Chromium     0.00005         0.2                              78 × 10⁶
  Thorium      0.00005         0.2                              78 × 10⁶
  Lead         0.00003         0.1                              46 × 10⁶
  Mercury      0.00003         0.1                              46 × 10⁶
  Gold         0.000004        0.02                              6 × 10⁶
  Radium       1 × 10⁻¹⁰       5 × 10⁻⁷                              150

  Adapted from _The Mineral Resources of the Sea_, by John L. Mero,
  American Elsevier Publishing Company, New York, 1964.

Many sea creatures are efficient, selective concentrators of “trace
elements”, which occur in seawater only in minute portions. These
elements are difficult enough to detect qualitatively and all but
impossible to analyze quantitatively. Yet among the elements the sea’s
plants and animals concentrate are the very materials with which we are
apt to be most concerned: Strontium, cesium, cerium, ruthenium, cobalt,
iodine, phosphorus, zinc, manganese, iron, chromium, and others.
Radioisotopes[6] of all these elements occur as by-products of human
nuclear activities. Many concentrating organisms are microscopic in size
and are frequently impossible to raise in captivity. It is apparent that
we are faced with a research program of considerable challenge and
proportion.

We need to know _how_ each marine species concentrates. Is it from the
food it eats, by absorption from the water, or both? Does it concentrate
an element by continuous accumulation, or is there a constant turnover
of the material in the organism’s system? (In the first case, once the
creature became radioactive it would remain so throughout its life or
until the radioactivity decayed. In the second case, however, the
radioactivity might be a transient condition, assuming the creature
could find its way into uncontaminated water and were able to flush
itself.) Obviously, both the cycling time of the radioisotope in the
organism and its radioactive half-life[7] must be taken into account.

Even if we should manage to identify all the marine concentrators and
gain some insight into their metabolic processes, this would be only a
first step. For example, one tiny form of planktonic protozoan,
_acantharia_, concentrates up to 15% of its own weight of strontium,
including the radioisotope strontium-90. It is eaten by larger
zooplankton (animals), such as copepods, which are eaten by little fish,
which, in turn, are eaten by bigger fish, etc. Somewhere along this food
chain, perhaps, a fish will come along that is favored for human dinner
tables. How much strontium-90 has _that_ fish accumulated through
swallowing its prey and by absorption from the water? Is the
radioactivity in its scales, bones, viscera, and other usually uneaten
portions, or in its flesh?

It is probable, though as yet by no means proven, that among the million
or so oceanic species of plant and animal life, there are concentrators
of virtually all the 60 or more elements found in seawater. To identify
and study them is an enormous undertaking, which is often possible only
by using radioisotopes as tools.

And what of the immediate and genetic effects of radiation on each
species? Studies of reef fish in the nuclear testing area in the
Marshall Islands have shown that radioiodine in the water caused thyroid
gland damage long after the amount of radioiodine remaining in the water
was too low to be detected. Studies of salmon in the Columbia River have
shown some physiological variations between those fish whose eggs and
young were reared in radioactive waters and those that were not, though
these variations have not been determined to be statistically
significant or different from variations caused by other contaminants.

Studies are being made of the reproductive efficiency and patterns of
sea creatures in a radiation-contaminated environment, compared with
those in an uncontaminated environment, to learn such things as the
numbers, survival rates, and sex ratios of the offspring, and any
genetic abnormalities or mutations. Many more studies are needed.
Always, the task is made difficult by insufficient detailed knowledge of
the original natural environment, the limitations of laboratory
experiments, and the mechanics of trying to follow the reproductive
cycles of free-floating or swimming organisms in any statistically
meaningful manner through successive generations.

One obviously important kind of research deals with the rate, pattern,
and means by which radionuclides are distributed into the sea from a
point source, such as the mouth of a river or a nuclear test site.
Transport and diffusion of radioactivity can be, and are, influenced by
physical, chemical, biological, or geological means, separately or all
at once. This has led the AEC to support scientific studies of currents,
upwelling, downwelling, convergence, diffusion, mixing rates, air-sea
interactions, chemical and geological processes in the sea, and the
horizontal and vertical migrations of sea life.

    [Illustration: _This sound instrument record reveals the layers of
    planktonic sound scatterers on the continental slope east of New
    England. Each peak originates from an individual group of
    organisms._]

In much of the ocean there is an acoustic “floor”, known as the _deep
scattering layer_ (because of what it does to sound waves), which is
believed to consist primarily of zooplankton. Every 24 hours the layer
migrates up and down through several hundred feet of water. At night the
countless small animals graze in the rich sea-plant pastures near the
surface; during daylight, back at the lower level, they undoubtedly are
heavily fed upon by larger animals. Over a period of time, the layer
accounts for considerable vertical transport of materials. (See figure
above.) Other life forms may move materials still farther down, or, in
some instances, back up—as when the sperm whale descends to the depths
to fight and best a giant squid, and then returns to the surface to eat
it.

Constantly drifting downward is a great volume of material—the dead
bodies, skeletons, excrement, and other waste from sea life at all
depths. As it sinks there is a constant exchange of matter between it
and the surrounding water through chemical, physical, and biological
processes. Eventually, the molecules of material added to the bottom
sediments may be returned to the water mass by bacteriological action or
the eating and living habits of sea floor animals.

    [Illustration: _A school of skipjack tuna photographed from an
    underwater observation chamber on the research vessel_ Charles H.
    Gilbert.]

Biological transport works in other ways, too. Most pelagic
(free-swimming) fish are great travelers. They account for a tremendous
movement of material, namely themselves, from one place to another.
Tuna, swordfish, whales, porpoises, and sea birds may travel thousands
of miles in a single year. Such migrations may serve, variously, as
mechanisms for either dispersal or concentration of elements or
nutrients. The anadromous (river-ascending) fishes, such as salmon,
herring, sturgeon, and shad, concentrate in freshwater streams in untold
numbers to spawn. After hatching, the young seek the ocean and scatter
widely until they, too, feel the urge to return to the rivers and lakes
whence they came, to spawn and die there as did their ancestors.

Ocean currents may transport concentrations of radionuclides essentially
undiluted for thousands of miles. Surface currents move at speeds of up
to five knots (nautical miles per hour). Normally current waters do not
mix readily with the water mass through which they pass. Because of the
slowness of vertical circulation in the ocean, radionuclides deposited
on the surface of the ocean may take a thousand years to reach the
bottom. But the vertical transport sometimes is much more rapid: When
the wind piles too much water against a coastline, the resultant
downwelling (sinking) may move radionuclides suddenly into the deeper
ocean. Or, conversely, when the wind and the rotation of the earth
combine to force the surface water _away_ from the coast, deep water may
suddenly rise to replace it, a process known as upwelling.

    [Illustration: _Mechanisms of nutrient turnover in the sea._]

    Light energy
    Dissolved gases
    Birds and man
    Rivers and ice
    Wave action
  Surface mixed layer 20-100m
    Suspended matter
    Elements in true solution
    Plants phytoplankton
    Animals
  Deep water
    Elements in true solution in deep water
  Buried in sediment
  Physical Processes
    _Transport by wind_
    _Transport by current_
    _Turbulent mixing_
    _Sedimentation_
    _Transport_ by animals
    _Volcanic action_
    _Diffusion_
  Chemical or Biological Processes
    _Photosynthesis_
    _Dissolving_
    _Upwelling_
    _Decomposition and respiration_
    _Sorption_ by sediment surface
    _Redissolving_ from sediment
    _Chemical precipitation_
  Combined Processes
    _Sedimentation and decomposition_ by bacteria
    _Scavenging_

Some recent evidence indicates that the passage of a hurricane across
the ocean drives surface water out from the storm center in all
directions. This, too, produces upwelling. If radionuclides fall on the
Arctic ice pack or on the Greenland or Antarctic ice caps, it may be
years before they are released to the sea. In more or less stable
conditions at sea, radionuclides may remain trapped above the
thermocline (a layer of sharp temperature change usually less than 100
meters below the surface) for a considerable period. Then a severe storm
may destroy the thermocline and mix the waters to much greater depths.
The process of diffusion in the ocean is not well understood, due both
to the difficulty of the measurements that have to be made and to the
variety of other factors affecting both vertical and horizontal
transport of materials. Here again, however, the existence of
radionuclides, introduced artificially at a known time and place, is
materially aiding these investigations by making a particular water mass
detectable and traceable.

    [Illustration: _Winds of 100 knots (about 115 mph) whip high waves
    in the Caribbean Sea east of Guadeloupe Island during a hurricane._]

In chemical oceanography, the AEC is concerned with the fact that in
some instances our society is introducing elements, ions, and compounds
that have not been naturally found in the sea, as well as natural
materials in greater concentration than is normal. These may combine
with other materials in the sea, changing into new forms or substances,
or removing them from solution entirely. Any change in the chemical
composition of the ocean is quite likely to have biological effects,
some of which may prove detrimental to man.

A disturbance of the chemical balance of the sea is thought to be
responsible, at least in part, for the periodic, disastrous plankton
“blooms” known as “red tides”. Such a sudden, explosive overpopulation
of plankton is a natural phenomenon, but one that can be triggered by
man-made pollution. When it occurs, plankton multiply so rapidly that
the oxygen in the water is depleted and many fish die from suffocation.

Fortunately, nuclear energy operations account for an extremely small
portion of the chemical contamination of the sea, when contrasted with
the tremendous volume of poisons dumped daily into it in the form of
other industrial and municipal waste and agricultural pesticides.


Research Projects

The AEC supports oceanographic research conducted by its own
laboratories and by other federal agencies, as well as by non-government
research scientists. The Environmental Sciences Branch of the Division
of Biology and Medicine has begun the long and complex task of
unraveling the mystery of the fate of radionuclides in the ocean.
Valuable techniques have been developed for the intentional injection of
radioisotopes into the sea for specific research. Scientists are now
able to conduct investigations that were never before possible. In some
instances, traditional scientific concepts and theories have been
shattered, or at least severely shaken, by new evidence gathered by
radioisotope techniques.

Since 70% of the earth’s surface is water, at least 70% of the
radioactive debris lofted into the stratosphere during atmospheric
nuclear weapons tests falls into the ocean. An additional small
proportion finds its way into the sea as the run-off from the land. In
the case of tests at sea, the majority of radiation immediately falls
into the water nearby. For this reason, the ocean around the sites in
the Marshall Islands where U. S. tests were conducted has provided a
unique opportunity to study the effect of large concentrations of
radionuclides. Particularly significant studies have been conducted of
the absorption of radionuclides by plants and animals living on nearby
reefs and islands, and of both lateral and vertical diffusion rates of
elements in the open ocean.[8]

The 1954 nuclear test at Eniwetok Atoll produced heavier-than-expected
local radioactive fallout. Since then, both American and Japanese
scientists have studied water-mass movement rates, using the fallout
radionuclides strontium-90 and cesium-137 themselves as tracer elements.
These nuclides produced in the test have been detected at depths down to
7000 meters in the far northwestern Pacific in the vicinity of Japan.

    [Illustration: _Autoradiograph of a plankton sample collected from a
    Pacific lagoon a week after a 1952 nuclear test, showing
    concentration of radioisotopes (bright areas)._]

If this results from simple eddy diffusion, as some scientists believe,
it is a case of diffusion at a very high rate. Other scientists suggest
that other factors may have contributed to the vertical transport of the
radionuclides to these depths. Still others believe that the
strontium-90 and cesium-137 might not have originated with the U. S.
Pacific tests at all, but rather with Russian tests in the Arctic taking
place at about the same time. They propose the theory that a syphoning
effect in the Bering Strait causes a current to flow out of the Arctic
Ocean and down under the surface waters of the western Pacific. In
support of this, Japanese researchers cite a dissolved oxygen content
where these measurements were made that is different from that of other
deep water in the area. If this theory should be proved correct, it
would be the first indication that such a current exists.

Similar investigations have been conducted of the variations in depth of
strontium-90 concentration in the Atlantic Ocean. In February 1962, when
fallout from 1961 nuclear tests was high, tests south of Greenland
showed that mixing of fallout was fairly rapid through the top 800
meters of water. At greater depths a colder, saltier layer of water
contained only about half as much strontium-90, confirming other
evidence that interchange between water masses of different physical and
chemical properties is comparatively low.

Work such as this has emphasized the difficulty in making meaningful
measurements of man-made radiation in the ocean. One problem is to
separate the artificially produced radiation from the natural radiation,
namely that from potassium-40 (which accounts for 97% of oceanic
radiation) and from the radionuclides, such as tritium, carbon-14,
beryllium-7, beryllium-10, aluminum-26, and silicon-32, created in the
stratosphere naturally by cosmic-ray bombardment.

    [Illustration: _In 1955 a scientific team aboard the U. S. Coast
    Guard vessel_ Roger B. Taney _conducted a survey of ocean fallout in
    the western Pacific. They collected marine organisms and water
    samples at various depths on their 17,500-mile, 7-week journey._]

Another problem is the sheer physical size of the water sample required
to get any measurements at all. Up to now there has been no truly
effective radiation counter that can be lowered over the side of a ship
to the desired depth. It is often necessary to collect a sample of many
gallons at great depths and return it to the surface without its being
mixed by any of the intervening water. This is difficult at best, and
only rather primitive methods have been developed. None is more than
partly satisfactory. A standard system is to lower a large, collapsed
polyethylene bag to the desired depth, open it, fill it, and close it
again, all by remote control, and then gingerly and hopefully return it
to the surface. Results do not always agree among samples taken at the
same location by different methods or by different scientists. There is
still no universal agreement among scientists as to the quantitative
validity of any of the measurements, although as more and better data
are gathered there tends to be a greater concurrence.

    [Illustration: _Fifty-gallon sampler ready to be lowered over the
    side of the research vessel_ Atlantis II _in the North Atlantic.
    Such devices are used to obtain samples at fixed intervals from the
    sea surface to the bottom. The water is analyzed for radioisotope
    content._]

Recently, under an AEC contract, a detector for direct measurements of
gamma radiation[9] in the deep ocean was developed for the Institute of
Marine Sciences, University of Miami, by the Franklin GNO Corp. (See
figure above.) This unit incorporates two of the largest plastic
scintillation counters[10] ever used in the ocean—each is 16 inches in
diameter by 12 inches thick. This apparatus may permit direct
qualitative and quantitative measurement of radiation at great depths by
techniques that will be eminently more satisfactory than water sampling.
Already tests with the detector have disclosed the existence of
cosmic-ray effects at much greater depths than heretofore known.

    [Illustration: _Scintillation counter for use in the deep ocean._]

    [Illustration: _Constituent parts. The plastic discs are the
    radiation detectors._]

Biologists from Woods Hole Oceanographic Institution in Massachusetts
for the first time have been able to measure the rate of excretion of
physiologically important fallout radionuclides by several species of
zooplankton—_pteropods_, _pyrasomes_, _copepods_, and _euphausids_.
Radioactive zinc and iodine, it was learned, are excreted as soluble
ions, while iron and manganese appear as solid particles. However, the
extent to which the intake and excretion of radionuclides and the
vertical migration of zooplankton contribute quantitatively to the
transport of radioactivity across the thermocline (and into the ocean
deeps) still can only be guessed.

    [Illustration: _Zooplankton, mostly copepods, collected with
    automatic underwater sampling equipment on board the nuclear
    submarine_ Seadragon _while cruising under the Arctic ice_.]

Other plankton research at Woods Hole uses radioactive carbon-14 and
phosphorus-32 as tracers to evaluate rates of growth and nutrient
assimilation by algae (floating green plants). These investigations have
revealed that the presence or absence of minute quantities of nutrient
minerals in seawater affects the rate at which the algae produce oxygen
by the process of photosynthesis. Since the energy of all living
things—including man—is also made available by photosynthesis, and since
most of the photosynthesis on earth is performed by algae afloat in the
oceans, it is apparent that this research is of more than academic
interest. Algae, the original energy-fixers of the “meadows of the sea”,
are also the original food source for the billions of aquatic animals,
and may some day prove a source of food for a mushrooming human
population.

In a project with more immediate application, extensive biological and
environmental studies of the Eniwetok Atoll area in the Pacific were
conducted prior to the first nuclear testing there in 1948, and these
studies have continued ever since. Early in the test series the
Japanese, who were at first concerned with the possible contamination of
their traditional marine food supplies, were invited to participate in
these studies. Fisheries radiological monitoring installations were
established in Japan and the U. S. (The latter was established by the
AEC and administered by the U. S. Food and Drug Administration.) Neither
station encountered any radiological contamination of tuna or other food
fish, and the American unit has now been closed.

    [Illustration: _This shell of the giant clam_ Tridacna gigas _shows
    the position of a layer of strontium-90 absorbed in 1958 (black
    line) and in 1956 (white line). The inside of the shell (light
    layers) was deposited in 1964 when the clam was collected at Bikini
    Atoll by scientists from the University of Washington, Seattle._]

Groups that have cooperated with the AEC in marine radiobiological
research are the University of Hawaii, University of Connecticut,
Virginia Fisheries Laboratory, University of Washington, U. S. Office of
Naval Research, and U. S. Bureau of Commercial Fisheries.

At the Bureau of Commercial Fisheries Radiobiological Laboratory in
Beaufort, North Carolina, a cooperative effort of the AEC and the BCF is
concerned with learning the effects of radioactive wastes on one of
America’s most valuable marine resources—the tidal marshlands and
estuaries that are essential to the continued well-being of some of our
important commercial fisheries.

       Table III RADIOISOTOPES THAT MIGHT BE FOUND IN AN ESTUARINE
                               ENVIRONMENT
               Isotope                            Half-life

  Iodine-131                          8.05 days
  Barium-140—Lanthanum-140            12.8 days—40 hours
  Cesium-141                          32.5 days
  Ruthenium-103—Rhodium-103           10 days—57 minutes
  Zirconium-95—Niobium-95             65 Days—35 days,
  Zinc-65                             245 days
  Cerium-144                          285 days
  Manganese-54                        314 days
  Ruthenium-106—Rhodium-106           1 year—30 seconds
  Cesium-137                          30 years
  Potassium-40                        1.3 × 10⁹ years

  (Reprinted from _Radiobiological Laboratory Annual Report_, April, 1,
  1964, page 50.)

The project has determined that radionuclides are removed from waters in
an estuarine environment by several physical, chemical, and biological
means. For example, radionuclides are absorbed in river-bed sediments at
a rate varying directly with sediment particle size. Mollusks, such as
clams, marsh mussels, oysters, and scallops, not only assimilate
radionuclides selectively, but do so in sufficient quantity and with
sufficient reliability to be useful as indicators of the quantity of the
isotopes present. Clams and mussels are indicators for cerium-144 and
ruthenium-106, scallops for manganese-54, and oysters for zinc-65 (most
of which winds up in the oyster’s edible portions). It was learned that
scallops assimilate more radioactivity than any other mollusk. Of the
total radioactivity, manganese-54 accounts for 60%: The scallop’s kidney
contains 100 times as much manganese-54 as any of the other tissues and
300 times as much as the muscle, the only part of the scallop usually
eaten in this country.

    [Illustration: _On the left are mussels collected near the Columbia
    River in an environment containing abnormal amounts of zinc-65._]

    [Illustration: _Mussels suspended in seawater in research to
    determine how fast they lose their zinc-65 radioactivity._
    (_Photograph taken at low tide._)]

In a surprising unintended result, it was determined that one acre of
oyster beds, comprising 300,000 individual oysters, may filter out the
radionuclides from approximately 10,000 cubic meters (18 cubic miles) of
water per week!

The Radiological Laboratory scientists also have found that plankton are
high concentrators of both chromium-51 and zinc-65, and that zinc
apparently is an essential nutrient for all marine organisms. Some
plants and animals appear to reach a peak of radionuclide accumulation
quickly, which then tapers off even though the radiation concentration
in the water is unchanged.

While the AEC’s oceanographic research budgets have not been large, they
have contributed materially to knowledge of the oceanic environment.
AEC-sponsored research at Scripps Institution of Oceanography has
determined by a process known as neutron activation analysis[11] that
the concentration of rare earth elements in Pacific Ocean waters appears
to be only about one hundredth of the level previously reported. By
analysis of naturally occurring radioisotopes, they have also discovered
that it takes from one million to 100 million years for lithium,
potassium, barium, strontium, and similar elements introduced into the
ocean from rivers to be deposited in the bottom sediments. Aluminum,
iron, and titanium are deposited in from 100 to 1000 years. They have
also found that sedimentation occurs in the South Pacific at a rate of
from 0.3 to 0.6 millimeter per thousand years, in the North Pacific at a
rate several times that figure, and in the basins on either side of the
Mid-Atlantic Ridge at a rate of several millimeters per thousand years.

The University of Miami has successfully developed two methods for
determining the ages of successive layers of deep ocean sediments based
on the relative abundances of natural radioelements, and thereby has
established a chronology of climatic changes during the last 200,000
years during which the sediments were laid down.

The U. S. is not alone in its use of nuclear energy as a tool of
science. The United Kingdom has carried out radiological studies of the
marine environment for many years, particularly concentrating on the
effects of radionuclides from nuclear power plants on the sea
immediately contiguous to the British Isles. Both the European Atomic
Energy Community and the International Atomic Energy Agency also
encouraged marine radiological studies. Many laboratories and government
agencies in Europe, North and South America, Africa, and the Middle East
and Far East have well-established and productive programs under way.

Scientists in many parts of the world have used both natural and
intentionally injected radiation to study the coastwise movement of
beach materials. British experimenters, for example, activate sand with
scandium-46 and are thus able to follow its movement for up to four
months. Pebbles (shingle) coated with barium-140 and lanthanum-140 are
also used as tracers and are good for 6 weeks. Scientists at the
University of California trace naturally occurring radioisotopes of
thorium, which may be introduced from deposits of thorium sands along
river banks. These studies are of immediate practical importance, for
each year the ocean moves billions of cubic yards of sand, gravel,
shingle, and rock to and from beaches and along shores. This action
destroys recreational beaches, fills channels, blocks off harbors, and
in general rearranges the terrain, often at considerable cost and
inconvenience to mariners and other people who use the coast.

In another use of radioisotopes in marine research, studies at the AEC’s
Oak Ridge National Laboratory in Tennessee have revealed radioactivity
in the scales of fish taken from waters affected by the laboratory’s
radioactive waste effluent. It was suggested that this phenomenon might
be put to use as a tagging technique in fish-migration studies, and
scientists are now working on a method using cesium-134 introduced into
the fishes’ natural diet.

    [Illustration: _Isaacs-Kidd midwater trawl collects samples of
    oceanic animals off the Oregon Coast. These animals are then
    radioanalyzed to compare the quantity of radioisotopes associated
    with animals from various depths. The recorder at the trawl mouth
    indicates the volume of water filtered._]

Some of the most extensive studies of a marine environment ever
conducted are those by the AEC, the Bureau of Commercial Fisheries, and
the University of Washington in the Columbia River system and the nearby
Pacific Ocean. Operations at the AEC’s giant Hanford facilities some 300
miles upstream from the ocean result in the release of small amounts of
radioactivity to the river and also in raising the river-water
temperature. This downstream research is to determine any effects of
these changes, including any that might be detrimental to man. The
research encompasses studies of the variations and distributions of the
freshwater “plume”—the outflow from the rivermouth—extending into the
nearby Pacific, sediment analyses, studies of the population dynamics of
phytoplankton, and the transport of radionuclides through the food
chain.

    [Illustration: _This core sampler is used to obtain stream bed
    samples up to 5 feet long in the Columbia River. The samples are
    then analyzed for radioisotope content._]

As so often happens with basic programs, this research has produced
immediate benefits. New resources of marketable oceanic fish were
discovered by the scientists at depths never before fished commercially
(from the edge of the continental shelf to depths of 500 fathoms and
greater). Similarly, commercial quantities of one species of crab have
been discovered in the deeper ocean. Other findings indicate that crab
populations may have seasonal up-and-down migrations that vary according
to sex. It appears, in fact, that, except while mating and as juveniles,
the male and female crab populations lead separate lives. This
information is important both for more efficient fisheries and for
improved conservation of the crab as a food resource.

The AEC is, in short, concerned with virtually every facet of basic
oceanography, and with study of the sea as a whole, for radionuclides,
like their nonradioactive counterparts, can and do become involved in
every phase of the vast and complex ocean ecology. In the process of
pursuing its research interests, it also provides oceanographers with a
whole new family of tools for study. Let us now see how atomic
instruments contribute to the growing knowledge of the sea.


Oceanographic Instruments

    [Illustration: _This radioisotope powered swimsuit heater uses
    plutonium-238 to produce 420 watts of heat. Water, heated by the
    decay of ²³⁸Pu, is pumped through plastic veins partially visible in
    the undergarment. The cylinder under the diver’s arm contains 4
    capsules of ²³⁸Pu, and a battery-pump assembly is contained in the
    box at his feet. After preliminary tests at the Naval Medical
    Research Institute in Bethesda, Maryland, the unit will be used in
    Sealab III, the Navy’s underwater research laboratory. The heater
    was developed by the AEC Division of Isotopes Development._]

The ocean is both a complex and a harsh environment and its study has
always demanded that designers of seaworthy instruments and sampling
devices be both ingenious and experienced in shipboard requirements.
Until recently, these devices tended to be rugged and simple, if not
indeed crude. More refined, electronic instrumentation has begun to
appear in recent years, but most designs still fail to pass the test of
use at sea. Even among those that do pass, there is persistent
difficulty in separating desired information-carrying signals from
background and system-induced “noise”. This has been a specific problem
with current meters designed to be moored in the open ocean and also
with one quite sophisticated gamma-ray detector.

To meet the clear need for improved devices, as well as to support its
own research and increase utilization of nuclear materials and
techniques, the AEC Division of Isotopes Development encourages the
development of oceanographic instrumentation. This comparatively young
technology already has produced exciting results. The future may be even
more revealing as nuclear energy is applied more and more to the study,
exploration, and exploitation of the ocean.

Instruments that have been developed under the AEC program include a
current meter, a dissolved-oxygen-content analyzer, and a
sediment-density meter. A new, fast method for determining the mineral
content of geological samples also has been perfected.


The DEEP WATER ISOTOPIC CURRENT ANALYZER (DWICA) was developed under a
contract with William H. Johnson Laboratories, Inc. It relies on
radioisotope drift time over a fixed course to measure seawater flow
rates ranging from 0.002 to 10.0 knots. The device embodies 12 radiation
sensors spaced equally in a circle around a radioisotope-injection
nozzle. Current direction can be determined to within 15 degrees. The
mass of tracer isotope injected is very small—less than 10 picograms[12]
per injection—and the instrument can store enough tracer material to
operate for a year. The tracer can be injected automatically at
intervals from 2 to 20 minutes, depending on the current. The device
sits on the sea floor, where its orientation to magnetic north can be
determined within 2.5 degrees.

    [Illustration: _The Deep Water Isotopic Current Analyzer._]

  Isotope Reservoir and equipressure system
  Electric logic circuitry
  Pressure protective case
  Compass
  Sensor ring
  Flow baffle plate
  Isotope injection point

    [Illustration: The Deep Water Isotopic Current Analyzer.]


A SEDIMENT DENSITY PROBE, developed under an AEC contract by Lane-Wells
Company, employs gamma-ray absorption and backscatter properties[13] to
determine the density of the sediments at the bottom of lakes, rivers,
or the ocean, without the necessity of returning a sediment sample to
the surface. It is expected that it can be modified to sense the water
content of the sediments. These determinations are valuable not only for
research, but also for activity that requires structures on the ocean
floor, such as petroleum exploration and naval operations.

    [Illustration: _The Sediment Density Probe. The drawing shows the
    complete probe._]

The unit consists of a rocket-like tube 26 feet long and about 4 inches
in diameter, containing a gamma-ray-emitting cesium-137 source, a lead
shield, and a radiation detector. The device is lowered over the side of
a ship and allowed to penetrate the sediment. Once in place, the gamma
ray source, shield, and detector move together up and down, inside the
probe, for a distance of 11 feet, stopping every 24 inches for 4 minutes
to take a measurement. Gamma rays are absorbed in any material through
which they pass, according to its density. A low radiation count at the
detector indicates a high-density sediment: More radiation is absorbed
and less is reflected back to the detector. Conversely, a high count
indicates low density. Data are recorded on special cold-resistant film.
A number of different sediment measurements can be made in several
locations before the unit must be returned to the surface.

    [Illustration: _Oxygen analyzer equipment includes the deep-sea
    probe (large device, center, including a special Geiger counter, the
    electronic assembly, a pump, and power supplies), cable for
    transmission of Geiger counter signals (back), and portable scaler
    (left)._]

    [Illustration: _The latter is also shown aboard a research vessel
    (inset) during tests made at sea._]


OXYGEN ANALYZER The amount of dissolved oxygen in any part of the ocean
is a basic quantity that must be determined before some kinds of
research can be undertaken. For example, oxygen concentration is
important in determining the life-support capability of seawater and in
measuring deep-water mixing. In the past this measurement has had to be
determined by laborious chemical methods that may subject the water
sample to contamination by exposure to atmospheric oxygen. Under an AEC
contract, the Research Triangle Institute has developed a dissolved
oxygen analyzer that relies on the quantitative oxidation by dissolved
oxygen of thallium metal containing a known ratio of radioactive
thallium-204.

The seawater sample passes through a column lined with thallium. The
thallium is oxydized and goes into solution. It then passes between two
facing pancake-shaped radiation counters that record the level of beta
radiation from the thallium-204. Since the rate of oxidation, and
therefore the rate of release of the thallium to solution, is
proportional to the amount of dissolved oxygen in the water, it is
simple to calibrate the device to show oxygen content. The system is
sensitive enough to detect one part of oxygen in 10 billion of water.
And, the device can be towed and take readings at depths of up to one
mile, an added advantage that obviates the chances of surface-air
contamination.


NEUTRON ACTIVATION ANALYSIS Nuclear energy is contributing to the more
accurate and more rapid analysis of minerals in the sea in at least two
different ways. The first employs neutron activation analysis, which we
have already mentioned. This method is valuable not only in analyzing
sediments cored from the ocean floor, but also in the detection and
quantitative analysis of trace elements in the water. Knowledge of the
role of all natural constituents in the ocean is essential to an
understanding of the complex interrelationships of the ocean
environment, as we have seen. Identification of trace elements also is a
necessary preliminary to determining the effects of purposely introduced
radionuclides. Collection of the minute quantities of trace elements is
very difficult at best. Once they have been collected and concentrated,
neutron activation analysis provides a means for their identification
and measurement.


X-RAY FLUORESCENCE is another technique, used to identify the mineral
content of ore or sediment. This system was developed (for the purpose
of spotting gold being smuggled through Customs) by Tracerlab Division
of Laboratory for Electronics, Inc. (LFE), under an AEC contract.
Similar equipment was developed simultaneously in England for use by
prospectors, geologists and mining engineers. It now may be used at sea
in analyzing samples from the sea floor. As is often the case with
isotope-based devices, its operation is really quite simple. When
excited by radiation from an isotope (or any other radiation source),
each element produces its own unique pattern of X-ray fluorescence, that
is, it radiates characteristic X rays. By varying filters and measuring
the count rate, oceanographers can detect and measure materials, such as
tin, copper, lead, and zinc. The British unit is completely
transistorized, battery powered, and weighs only 16.5 pounds.


RHODAMINE-B DYE The AEC also has improved oceanographic research in ways
that do not involve the use of nuclear energy. Some years ago under the
joint sponsorship of the AEC Division of Reactor Development and
Technology and the Division of Biology and Medicine, the Waterlift
Division of Cleveland Pneumatic Tool Company developed instrumentation
and techniques for detecting the presence of the red dye, rhodamine-B,
in concentrations as low as one-tenth part per billion. This method is
now widely used both for groundwater studies and in the study of
currents, diffusion, and pollution in rivers, lakes, and the ocean. In
many cases, rhodamine-B is a better tracer in water than radioisotopes,
due to the greater ease with which it is detected.


Environmental Safety Studies

The AEC Division of Reactor Development and Technology has supported
extensive environmental studies to assess the safety of isotopic power
sources (to be discussed later) in oceanic environments. One of the most
important of these is being conducted by the Naval Radiological Defense
Laboratory at an ocean environmental testing complex near San Clemente
Island off the coast of California, which includes a shore installation
and a floating ocean platform. These studies are to determine seawater
corrosion of containment alloys and fuel solubility in seawater; the
dispersion of the fuel in the ocean; the effect of the radioactive
material on marine life; and the radiation hazard to man, when all
significant exposure pathways are considered.

In another study the Chesapeake Bay Institute of Johns Hopkins
University investigated potential hazards that might result if
radioactive materials were released off the Atlantic Coast. Five areas
along the Continental Shelf were examined in detail for environmental
factors such as vertical diffusion. The same Institute made
environmental and physical dispersion studies off Cape Kennedy, Florida,
to predict the fate of any radioactive materials that might be released
in aborted launchings of nuclear rockets or nuclear auxiliary power
devices for space uses. Fluorescent dye was released into offshore, surf
zone, and inshore locations; the diffusion was observed, sampled, and
compared with existing diffusion theory. Mathematical models have been
developed that can now be used to predict the rate and extent of
diffusion in the Cape Kennedy area in the event of any radioactivity
release from aborted test flights.

Similar studies have been carried out near the space launching site at
Point Arguello, California, by the Scripps Institution of Oceanography.
These included collection of data on dispersion, marine sediments, and
the biological uptake of radioactive plutonium, polonium, cesium, and
strontium.


The Atom at Work in the Sea

NUCLEAR REACTOR PROPULSION

The transformation in undersea warfare tactics and national defense
strategy effected by the introduction of nuclear-powered submarines is
now well known. Navy submarines employing the latest reactors and fuel
elements can stay at sea for more than 3 years without refueling.
_Polaris_ submarines on patrol remain submerged for 60 to 70 days. The
nuclear submarine _Triton_, tracing Magellan’s route of 400 years
earlier, traveled 36,000 miles under water, moving around the world in
83 days and 10 hours. Under-ice transits of the Arctic Ocean by nuclear
submarines are now commonplace. These feats all are possible because of
the nuclear reactors and propulsion systems developed by the AEC
Division of Naval Reactors, which also developed the propulsion plants
for the Navy’s nuclear surface vessels.[14]

    [Illustration: _USS_ Seadragon _and_ Skate _sit nose to nose on top
    of the world after under-ice voyages from the Atlantic and Pacific
    Oceans to the North Pole._]

    [Illustration: _A frogman from the Seadragon swims under the Arctic
    ice in one of the first photographs made beneath the North Pole._]


DEEP SUBMERGENCE RESEARCH VEHICLE On April 18, 1965, President Johnson
announced that the Atomic Energy Commission and Department of the Navy
were undertaking development of a nuclear-powered deep submergence
research and engineering vehicle. This manned vehicle, designated the
NR-1, will have vastly greater endurance than any other yet developed or
planned, because of its nuclear power. Its development will provide the
basis for future nuclear-powered oceanographic research vehicles of even
greater versatility and depth capability.

The NR-1 will be able to move at maximum speed for periods of time
limited only by the amount of food and supplies it carries. With a crew
of five and two scientists, the vehicle will be able to make detailed
studies of the ocean bottom, temperature, currents, and other phenomena
for military, commercial, and scientific uses. The nuclear propulsion
plant will give it great independence from surface support ships and
essentially unlimited endurance for exploration.

The submarine will have viewing ports for visual observation of its
surroundings and of the ocean bottom. A remote grapple will permit
collection of marine samples and other objects. The NR-1 is expected to
be capable of exploring areas of the Continental Shelf, which appears to
contain the most accessible wealth in mineral and food resources in the
seas. Exploratory charting of this kind may help the United States in
establishing sovereignty over parts of the Continental Shelf; a ship
with its depth capability can explore an ocean-bottom area several times
larger than the United States.

The reactor plant for the vehicle is being designed by the General
Electric Company’s Knolls Atomic Power Laboratory, Schenectady, New
York. The remainder of the propulsion plant is being designed by the
Electric Boat Division, General Dynamics Corporation, Groton,
Connecticut.

Scientists are already beginning to implant small sea floor
laboratories. In the future, when large permanent undersea installations
for scientific investigation, mining, or fish farming become a reality,
nuclear reactors like the one designed for research submersibles or the
one already in use in Antarctica and other remote locations[15] will
serve as their power plants.

ISOTOPIC POWER SOURCES

The ocean is a logistically remote environment, in the sense that
conventional combustible fuels can’t be used underwater unless supplied
with their own sources of oxygen. It is usually extremely costly to take
anything heavy or bulky into the deep ocean. Even if the two essential
components of combustion—fuel and oxygen—could be delivered economically
to an undersea base or craft, the extreme back pressure of the depths
would present serious exhaust problems. Yet deep beneath the sea is just
where we now propose to do large amounts of work requiring huge supplies
of reliable energy. The lack of reliable and extended duration power
sources is perhaps one of the most critical requirements for expansion
of underwater and marine technology. For example, the pressing need for
measurements of atmospheric and oceanic data to support scientific,
commercial, and military operations will in the future require literally
hundreds of oceanographic and meteorological buoys deployed throughout
the world to take simultaneous measurements and time-series observations
at specific sites.

Some of these buoys will support and monitor up to 100 sensors each.
These devices record a variety of physical, chemical, and radiological
phenomena above, at, or below the surface. Periodically the sensor data
will be converted to digital form and stored on magnetic tape for later
retrieval by distant shore-based or shipboard radio command, by
satellite command (for retransmittal to ground stations), or by physical
recovery of the tapes. Individually, each buoy will not require a great
deal of energy to operate, but will have to operate reliably over long
periods of time. Conventional power sources are being used for the
prototype buoys now under development and testing, but these robot ocean
platforms in the future will make excellent use of nuclear energy
supplied by isotopic power sources.

    [Illustration: _The world’s first nuclear-powered weather buoy
    located in the center of the Gulf of Mexico. This weather station,
    part of the U. S. Navy’s NOMAD system, is on a barge 10 feet × 20
    feet, and is anchored in 12,000 feet of water._]

    [Illustration: diagram]

  RADIO ANTENNA
  WEATHER SENSORS
  WARNING BEACON
  NUCLEAR GENERATOR

The SNAP-7D isotope power generator has been operating unattended since
January 1964 on a deep-ocean moored buoy in the Gulf of Mexico. This U.
S. Navy NOMAD (Navy Oceanographic and Meteorological Automatic Device)
buoy is powered by a 60-watt, strontium-90 radioisotope source, which
was developed by the AEC Division of Reactor Development and Technology.
This weather station transmits data for 2 minutes and 20 seconds every 3
hours. This data includes air temperature, barometric pressure, and wind
velocity and direction. Storm detectors trigger special hourly
transmissions during severe weather conditions. The generator operates
continuously and charges storage batteries between transmissions. Some
power is used to light a navigation beacon to alert passing ships.

Energy from the heat of radioisotope decay has been used on a
“proof-of-principle” basis in several other instances involving ocean or
marine technology.

An experimental ⁹⁰Sr isotope-powered acoustic navigation beacon
(SNAP-7E) now rests on the sea floor in 15,000 feet of water near
Bermuda. Devices such as these not only will enable nearby surface
research or salvage vessels to locate their positions precisely
(something very difficult to do at sea) and to return to the same spot,
but the beacons also will aid submarine navigation (see page 48).

A U. S. Coast Guard lighthouse located in Chesapeake Bay has been
powered by a 60-watt, ⁹⁰Sr power source, SNAP-7B, for 2 years without
maintenance or service. This unit was subsequently relocated for use in
another application (described below).

    [Illustration: _Engineers prepare to install the SNAP-7D
    generator._]

The first commercial use of one of these “atomic batteries” began in
1965 when the SNAP-7B 60-watt generator went into operation on an
unmanned Phillips Petroleum Company offshore oil platform, 40 miles
southeast of Cameron, Louisiana. The generator operates flashing
navigational lights and, in bad weather, an electronic foghorn (see page
49). This unit will be tested for 2 years to determine the economic
feasibility of routinely using isotopic power devices on a commercial
basis.

    [Illustration: Acoustic pulses.]

  Buoyancy tank
  Sound amplifier
  Nuclear-powered sound source
  Ocean bottom

    [Illustration: _The SNAP-7E isotopic generator powers an undersea
    acoustic beacon, which produces an acoustic pulse once every 60
    seconds. In addition to being a navigation aid, the beacon is used
    to study the effects of a deep-ocean environment on the transmission
    of sound over long distances._]

    [Illustration: Diagram.]

  Total height: 10 ft 2 in
  Armored cable
  Pressure vessel
  Capacitor bank
  Fuel capsules
  Biological shield
  Equipment package
  Voltage converter
  Depleted uranium
  Thermoelectric generator
  System support structure

    [Illustration: _Details of the Phillips Petroleum platform, which
    uses the SNAP-7B nuclear generator._]

    [Illustration: _The final electrical connection is made from the
    nuclear generator to the platform’s electronic foghorn and two
    flashing light beacons._]

    [Illustration: Diagram]

  Fog Horn
  Beacon
  Beacon
  Snap-7B nuclear generator

The radioisotope-powered devices previously described were developed by
the AEC under the SNAP-7 Program.[16] The testing of these units has
demonstrated the advisability of developing reliable and unattended
nuclear power sources for use in remote environments without compromise
to nuclear safety standards. As a result of the success of these tests,
a variety of potential oceanographic applications have been identified.
A study, conducted by Aerojet-General Corporation in conjunction with
Global Marine Exploration Company and Northwest Consultant
Oceanographers, Inc., described ocean applications including underwater
navigational aids, acoustic beacons, channel markers, cable boosters,
weather buoys, offshore oil well controls along with innumerable
oceanographic research applications. This study was sponsored by the AEC
Division of Isotopes Development.

In order to satisfy the requirements for these and other applications,
the AEC has begun developing a series of compact and highly reliable
isotope power devices that are designed to be economically competitive
with alternative power sources. Currently underway are two specific
projects, SNAP-21 and SNAP-23.

SNAP-21 is a two-phase project to develop a series of compact
strontium-90 power systems for deep-sea and ocean-bottom uses
(20,000-foot depths). The first phase of design and component
development on a basic 10-watt system already has been completed, and a
second phase development and test effort now under way will extend
through 1970. A series of power sources in the 10- and 20-watt range
will be available for general purpose deep-ocean application.

The SNAP-23 project involves the development of a series of economically
attractive strontium-90 power systems for remote terrestrial uses. This
project will result in 25-watt, 60-watt, and 100-watt units capable of
long-term operation in surface buoys, offshore oil platforms, weather
stations, and microwave repeater stations.

In addition to the above, effort is underway by the AEC to develop an
isotope-fueled heater that will be used by aquanauts in the Navy’s
Sealab Program (see page 12). Future activities, now being planned, will
involve the development of large isotope power sources (1-10 electric
kilowatts) and small nuclear reactors (50-100 kilowatts) for use in
manned and unmanned deep-ocean platforms.


Ocean Engineering

Considerable engineering experience has been derived from the work of
federal agencies in development of the largest taut-moored instrumented
buoy system ever deployed in the deep ocean. Developed by Ocean Science
81 Engineering, Inc., it is useful in observation and prediction of
environmental changes.

The system embodies substantial advances in design. It incorporates,
among other features, an acoustically commanded underwater winch for
adjustment of the mooring depth after the buoy is deployed, and for
recovering a 16,000-pound submerged data-recording instrument canister.
This buoy system can survive being moored in up to 18,000-foot depths of
the open ocean for upward of 30 days.

The very first deep-ocean, taut-moored buoy system was developed for the
government in 1954, and has since become an important tool for
oceanographers and others who seek stable instrument platforms at sea.
The buoys have the advantage of minimizing horizontal movement due to
currents, winds, and waves.

The National Marine Consultants Division of Interstate Electronics
Corporation has developed for the government a system for measuring the
propagation of seismic sea waves (tsunamis).

Work of these sorts contributes materially to reliable ocean
engineering. And the measurements made by these sophisticated
instruments contribute to our knowledge of ocean fluid dynamics and wave
mechanics.

Corrosion is a huge, ever-present problem plaguing oceanographic
engineers, ship designers, mariners, operators of desalination plants,
petroleum companies with offshore facilities, and, in fact, everyone who
places structures in salt water to do useful work. While the basic
mechanisms of corrosion are known, there are many detailed aspects that
are not: For example, the precise role of bacteriological slimes in
causing corrosion on supposedly protected structures. Radioisotope
tracers now are helping engineers follow the chemical, physical, and
biological actions in corrosion processes.


Fresh Water from Seawater

In 1960 the chairman of the board of a large U. S. corporation made a
fundamental policy decision for his company: Since the greatest critical
need of man in the next decade would be fresh water, his company would
begin working to produce large volumes of fresh water—including the
development of methods for desalting seawater. His pioneering analysis
proved to be prophetic.

Throughout the world, more people are using more water for more purposes
than ever before. Many areas of the world, including some that are
densely populated, have been parched since the dawn of history. In
others where water was once abundant, not only are natural sources being
depleted faster than they are replaced, but many rivers and lakes have
been so polluted that they can now scarcely be used.

The world’s greatest resource of water is the ocean, but energy is
required to remove the salt from it and make it potable or even useful
for agriculture and industry. The energy produced by nuclear reactors is
considered economical in the large quantities that soon will be
required.

The AEC and the Office of Saline Water of the Department of the
Interior, after a preliminary study, have joined with the Metropolitan
Water District of Southern California and the electric utility firms
serving the area, to begin construction of a very large nuclear-power
desalting plant on a man-made island off the California coast. The
plant, when completed in the 1970s, will have an initial water capacity
of 50 million gallons per day and also will generate about 1,800,000
kilowatts of electricity. Additional desalting capacity is planned for
addition later to achieve a total water capacity of 150 million gallons
per day.

    [Illustration: _Plans to construct a nuclear desalting plant in
    California were announced in August 1966 by (from left) AEC
    Commissioner James T. Ramey, Secretary of the Interior Stewart L.
    Udall, Mayor Samuel Yorty of Los Angeles, and Joseph Jensen, Board
    Chairman of the Metropolitan Water District of Southern
    California._]

Plans for other nuclear-powered desalting projects around the world are
being discussed by the United States government, the International
Atomic Energy Agency and the governments of many other nations. Some of
these also may be in operation during the early 1970s.[17]

    [Illustration: _Model of the nuclear power desalting plant to be
    built on the coast of Southern California._]

These projects followed extended detailed studies, including one
“milestone” investigation at the AEC’s Oak Ridge National Laboratory in
Tennessee, in which the economic feasibility of using very large nuclear
reactors coupled to very large desalting equipment to produce power and
water was determined.

The significance of these studies was recognized by President Johnson in
1964, when he told the Third International Conference on Peaceful Uses
of Atomic Energy: “The time is coming when a single desalting plant
powered by nuclear energy will produce hundreds of millions of gallons
of fresh water—and large amounts of electricity—every day.”

It is obvious that today realization of that goal is much nearer.

The installation of new and larger desalting plants will in itself
require extensive additional oceanographic research. By the nature of
their operation these plants will be discharging considerable volumes of
heated water with a salt content higher than that of the sea. Throughout
the ocean, but particularly in the estuaries, sea life is sensitive to
the concentration of ocean salts and temperature. Studies of the effect
of such discharges will be an essential part of any large-scale
desalination program.


Radiation Preservation of Seafood

The use of nuclear radiation for the preservation of food is a new
process of particular importance for seafood. The ocean constitutes the
world’s largest source of animal protein food. Yet the harvests of the
sea can be stored safely, even with refrigeration, for far shorter
periods than can most other foods. In many parts of the world, this
tendency to spoil makes fish products available only to people who live
near seacoasts.

Many types of seafood, however, when exposed to radiation from
radioisotopes or small accelerators, can be stored under normal
refrigeration for up to four weeks without deterioration. The process
does not alter the appearance or taste of the seafood; it merely
destroys bacteria that cause spoilage. This fact holds promise not only
for the world’s protein-starved populations, but also for the economic
well-being of commercial fishermen, whose markets would be much
expanded.

In support of this program, the AEC has built and is operating at
Gloucester, Massachusetts, a prototype commercial seafood irradiator
plant capable of processing 2000 pounds of seafood an hour. The
radiation is supplied by a cobalt-60 source. Private industry is
cooperating with the AEC in the evaluation of this facility.[18]

    [Illustration: _The first shipboard irradiator was on The_ Delaware,
    _a research fishing vessel. Fish, preserved through irradiation soon
    after they are caught, have a refrigerated storage life two or three
    times longer than nonirradiated fish._]

    [Illustration: _The first shipboard irradiator._]


Project Plowshare

Nuclear explosives are, among other things, large-scale, low-cost
excavation devices. In this respect, with the proper pre-detonation
study and engineering, they are ideally suited for massive earth-moving
and “geological engineering” projects, including the construction of
harbors and canals. The western coasts of three continents, Australia,
Africa, and South America, are sparsely supplied with good harbors. A
number of studies have been undertaken as to the feasibility of using
nuclear explosives for digging deepwater harbors. Undoubtedly at some
time in the future, these projects will be carried out.

In addition, there are many places in the world where the construction
of a sea-level canal would provide shorter and safer routes for ocean
shipping, expedite trade and commerce, or open up barren and
unpopulated, but mineral-rich lands to settlers and profitable
development. The AEC Division of Peaceful Nuclear Explosives operates a
continuing program to develop engineering skills for such projects.[19]
Construction of a sea-level canal across the Central American isthmus is
one well-known proposal for this “Plowshare” program.

The use of nuclear explosives in this manner may one day change the very
shape of the world ocean.


A New _Fram_

    [Illustration: _Fridtjof Nansen_]

Just about 70 years ago, the oceanographer and explorer, Dr. Fridtjof
Nansen completed his famous voyage aboard the research vessel _Fram_,
which remained locked in the Arctic ice pack for 3 years, drifting
around the top of the world while the men aboard her studied the
oceanography of the polar sea. Now the National Science Foundation has
taken the first steps toward building a modern version of _Fram_ for
Arctic studies. This time the vessel will be an Arctic Drift Barge
containing the best equipment modern technology can offer—including, it
is proposed, a central nuclear power plant to guarantee heat and power.
Scheduled for completion sometime in the 1970s, this project represents
yet another use of the atom in the study of the ocean.




                      THE THREE-DIMENSIONAL OCEAN


The ocean is no longer an area of isolated scientific interest, nor
merely a turbulent two-dimensional surface over which man conducts his
commerce and occasionally fights his wars.

In today’s world, the ocean has assumed its full third dimension. Men
and women are going down into it to study, to play, to work, and, alas,
sometimes to fight. As they go, they are taking atomic energy with them.
In many instances, only the harnessed power in the nuclei of atoms
permits them to penetrate the depths of the mighty sea and there attain
their objectives.

    [Illustration: _Artist’s conception of one of three proposed designs
    for the National Science Foundation’s Arctic Drift Barge. All three
    designs incorporate a nuclear power source._]




                          SUGGESTED REFERENCES


Books

_The Bountiful Sea_, Seabrook Hull, Prentice-Hall, Inc., Englewood
      Cliffs, New Jersey 07632, 1964, 340 pp., $6.95.

_This Great and Wide Sea_, R. E. Coker, Harper & Row, New York 10016,
      1962, 235 pp., $2.25 (paperback).

_Exploring the Secrets of the Sea_, William J. Cromie, Prentice-Hall,
      Inc., Englewood Cliffs, New Jersey 07632, 1962, 300 pp., $5.95.

_The Sea Around Us_, Rachel L. Carson, Oxford University Press, Inc.,
      New York 10016, 1961, 237 pp., $5.00 (hardback); $0.60 (paperback)
      from the New American Library of World Literature, Inc., New York
      10022.

_The Ocean Adventure_, Gardner Soule, Appleton-Century, New York 10017,
      1966, 278 pp., $5.95.

_Proving Ground: An Account of the Radiobiological Studies in the
      Pacific, 1946-1961_, Neal O. Hines, University of Washington
      Press, Seattle, Washington 98105, 1962, 366 pp., $6.75.

_The Effects of Atomic Radiation on Oceanography and Fisheries_
      (Publication 551), National Academy of Sciences—National Research
      Council, Washington, D. C. 20418, 1957, 137 pp., $2.00.

_Oceanography: A Study of Inner Space_, Warren E. Yasso, Holt Rinehart
      and Winston, Inc., New York, 10017, 1965, 176 pp., $2.50
      (hardback); $1.28 (paperback).


Booklets

_Oceanography Information Sources_ (Publication 1417), National Academy
      of Sciences—National Research Council, Washington, D. C. 20418,
      1966, 38 pp., $1.50.

_A Reader’s Guide to Oceanography_, Jan Hahn, Woods Hole Oceanographic
      Institution, Woods Hole, Massachusetts 02543, August 1965 (revised
      periodically) 13 pp., free.


The following booklets are available from the Superintendent of
Documents, U. S. Government Printing Office, Washington, D. C. 20402:

_Undersea Vehicles for Oceanography_ (Pamphlet No. 18), Inter-agency
      Committee on Oceanography of the Federal Council for Science and
      Technology, 1965, 81 pp., $0.65.

_Marine Sciences Research_, AEC Division of Biology and Medicine, March
      1966, 18 pp., $0.15.


Articles

Tools for the Ocean Depths, _Fortune_, LXXII: 213 (August 1965).

Journey to Inner Space, _Time_, 86: 90 (September 17, 1965).

Working for Weeks on the Sea Floor, Jacques-Yves Cousteau, _National
      Geographic_, 129: 498 (April 1966).

_Nucleonics_, 24 (June 1966). This special issue on the use of the atom
      undersea contains the following articles of interest:

Reactors: Key to Large Scale Underwater Operations, J. R. Wetch, 33.

Undersea Role for Isotopic Power, K. E. Buck, 38.

Radioisotopes in Oceanographic Research, R. A. Pedrick and G. B. Magin,
      Jr., 42.


Motion Pictures

_1000 Feet Deep for Science_, 27 minutes, color, 1965. Produced by and
      available from Westinghouse Electric Corporation, Visual
      Communications Department, 3 Gateway Center, Box 2278, Pittsburgh,
      Pennsylvania 15230. This film describes the Westinghouse Diving
      Saucer, which is a two-man laboratory used for underwater
      research. This is the saucer that is used by Jacques-Yves Cousteau
      and was featured in his motion picture _World Without Sun_.


Available for loan without charge from the AEC Headquarters Film
Library, Division of Public Information, U. S. Atomic Energy Commission,
Washington, D. C. 20545 and from other AEC film libraries.

_Bikini Radiological Laboratory_, 22 minutes, sound, color, 1949.
      Produced by the University of Washington and the AEC. This film
      explains studies of effects of radioactivity from the 1946 atomic
      tests at Bikini Atoll on plants and marine life in the area 3
      years later.

_Return to Bikini_, 50 minutes, sound, color, 1964. Produced by the
      Laboratory of Radiation Biology at the University of Washington
      for the AEC. This film records the ecological resurvey of Bikini
      in 1964, 6 years after the last weapons test.

_Desalting the Seas_, 17 minutes, sound, color, 1967. Produced by AEC’s
      Oak Ridge National Laboratory. Describes various methods of
      purifying saline water through the use of large dual-purpose
      nuclear-electric desalting plants.

    [Illustration: uncaptioned]


PHOTO CREDITS

 Page
 2           U. S. Navy (USN)
 3           University of Pennsylvania Museum—National Geographic
                  Expedition
 5           USN
 6           Woods Hole Oceanographic Institution (WHOI)
 7           Diagram, WHOI; photo, S. Hull
 9           Top, Oregon State University (OSU); bottom, University of
                  California, San Diego, Scripps Institution of
                  Oceanography (SIO)
 10          Lamont Geological Observatory of Columbia University
 12          USN
 15          SIO
 19          R. H. Backus. _Physics Today_ (November 1965), “Sound
                  Reflections In and Under Oceans,” J. B. Hersey
 20          U. S. Bureau of Commercial Fisheries Biological Laboratory,
                  Honolulu, Hawaii
 22          USN
 24          Laboratory of Radiation Biology, University of Washington
                  (LRB)
 26          Jan Hahn
 27          Franklin GNO Corporation
 28          George D. Grice, WHOI
 31          SIO
 33          OSU
 35          Monsanto Research Corporation
 37          USN
 38          Lane-Wells Company
 39          Research Triangle Institute
 43          USN
 46, 47 & 48 Martin-Marietta Company
 49          The Photo Mart
 53          Top, Metropolitan Water District of Southern California;
                  bottom, Bechtel Corporation
 55          U. S. Bureau of Commercial Fisheries, Fish and Wildlife
                  Service; inset, Brookhaven National Laboratory
 56          Norsk Folkemuseum, Oslo, Norway, courtesy The Mariners
                  Museum, Newport News, Virginia
 57          National Science Foundation
 61          S. Hull
 Cover photo courtesy James Butler, USN
 Author’s photo courtesy General Dynamics Corporation
 Frontispiece from Jan Hahn


THE COVER

    [Illustration: The ATOM and the OCEAN]

The ship on the cover is the trim _Atlantis_ riding the waves about 200
miles south of Bermuda. The first craft built by the United States as an
oceanographic research vessel, she traveled more than 1,200,000 miles
across the seven seas for a period of 30 years. She “ran” over 6000
hydrographic stations and was used for innumerable dredging, coring,
biological, physical, and acoustical research operations. After she was
retired from active service at the Woods Hole Oceanographic Institution
in Massachusetts, she was sold to Argentina, where she has resumed her
role as an oceanographic research vessel.


THE AUTHOR

E. W. SEABROOK HULL is an experienced writer and editor in technical and
engineering fields. He is the author of _The Bountiful Sea_, published
in 1964 by Prentice-Hall, and _Plowshare_, another booklet in this
Understanding the Atom Series. He is the editor of _Ocean Science News_
and editor and publisher of _GeoMarine Technology_.

    [Illustration: E. W. Seabrook Hull]




                               Footnotes


[1]For a description of how these will work, see _Controlled Nuclear
    Fusion_, another booklet in this series.

[2]These devices, which will be frequently mentioned later in these
    pages, are described in detail in a companion booklet _Power from
    Radioisotopes_.

[3]See _Nuclear Reactors_, another booklet in this series, for a
    description of the fission process and how reactors operate.

[4]For a full discussion of other aspects of this topic, see _Fallout
    from Nuclear Tests_, another booklet in this series.

[5]For a full discussion of this topic, and the safety measures taken by
    the AEC in connection with it, see _Radioactive Wastes_, another
    booklet in this series.

[6]Radioisotopes, unstable forms of ordinary atoms, are distinguishable
    by reason of their radioactivity, not by their biological or
    chemical activity.

[7]The time in which half of the atoms in a quantity of radioactive
    material lose their radioactivity.

[8]For more details of these studies, see _Atoms, Nature, and Man_, a
    companion booklet in this series.

[9]Gamma rays are high-energy electromagnetic radiation, similar to X
    rays, originating in the nuclei of radioactive atoms.

[10]Instruments that detect and measure radiation by recording the
    number of light flashes or scintillations produced by the radiation
    in plastic or other sensitive materials.

[11]A method involving use of nuclear reactors or accelerators for
    identifying extremely small amounts of material. See _Neutron
    Activation Analysis_, a companion booklet in this series.

[12]A picogram is one trillionth (10⁻¹²) of a gram.

[13]For an explanation of how similar instruments work, see
    _Radioisotopes in Industry_, a companion booklet in this series.

[14]For a discussion of proposed nuclear merchant submarines, see
    _Nuclear Power and Merchant Shipping_, another booklet in this
    series.

[15]These are described in _Power Reactors in Small Packages_, another
    booklet in this series.

[16]See _Power from Radioisotopes_, a companion booklet in this series,
    for a more complete discussion of radioisotopes in use.

[17]For an explanation of how these will function, see _Nuclear Energy
    for Desalting_, another booklet in this series.

[18]See _Food Preservation by Irradiation_, another booklet in this
    series, for a full account of this installation.

[19]Details are described in _Plowshare_, another booklet in this
    series.


This booklet is one of the “Understanding the Atom” Series. Comments are
invited on this booklet and others in the series; please send them to
the Division of Technical Information, U. S. Atomic Energy Commission,
Washington, D. C. 20545.

Published as part of the AEC’s educational assistance program, the
series includes these titles:

  _Accelerators_
  _Animals in Atomic Research_
  _Atomic Fuel_
  _Atomic Power Safety_
  _Atoms at the Science Fair_
  _Atoms in Agriculture_
  _Atoms, Nature, and Man_
  _Books on Atomic Energy for Adults and Children_
  _Careers in Atomic Energy_
  _Computers_
  _Controlled Nuclear Fusion_
  _Cryogenics, The Uncommon Cold_
  _Direct Conversion of Energy_
  _Fallout From Nuclear Tests_
  _Food Preservation by Irradiation_
  _Genetic Effects of Radiation_
  _Index to the UAS Series_
  _Lasers_
  _Microstructure of Matter_
  _Neutron Activation Analysis_
  _Nondestructive Testing_
  _Nuclear Clocks_
  _Nuclear Energy for Desalting_
  _Nuclear Power and Merchant Shipping_
  _Nuclear Power Plants_
  _Nuclear Propulsion for Space_
  _Nuclear Reactors_
  _Nuclear Terms, A Brief Glossary_
  _Our Atomic World_
  _Plowshare_
  _Plutonium_
  _Power from Radioisotopes_
  _Power Reactors in Small Packages_
  _Radioactive Wastes_
  _Radioisotopes and Life Processes_
  _Radioisotopes in Industry_
  _Radioisotopes in Medicine_
  _Rare Earths_
  _Research Reactors_
  _SNAP, Nuclear Space Reactors_
  _Sources of Nuclear Fuel_
  _Space Radiation_
  _Spectroscopy_
  _Synthetic Transuranium Elements_
  _The Atom and the Ocean_
  _The Chemistry of the Noble Gases_
  _The Elusive Neutrino_
  _The First Reactor_
  _The Natural Radiation Environment_
  _Whole Body Counters_
  _Your Body and Radiation_

A single copy of any one booklet, or of no more than three different
booklets, may be obtained free by writing to:

            USAEC, P. O. BOX 62, OAK RIDGE, TENNESSEE 37830

Complete sets of the series are available to school and public
librarians, and to teachers who can make them available for reference or
for use by groups. Requests should be made on school or library
letterheads and indicate the proposed use.

Students and teachers who need other material on specific aspects of
nuclear science, or references to other reading material, may also write
to the Oak Ridge address. Requests should state the topic of interest
exactly, and the use intended.

In all requests, include “Zip Code” in return address.


                Printed in the United States of America
USAEC Division of Technical Information Extension, Oak Ridge, Tennessee




                          Transcriber’s Notes


—Silently corrected a few typos.

—Retained publication information from the printed edition: this eBook
  is public-domain in the country of publication.

—In the text versions only, text in italics is delimited by
  _underscores_.