Chapter II: Part 2

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]

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.

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).

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.

Buoyancy tank
Sound amplifier
Nuclear-powered sound source
Ocean bottom

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

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.

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]

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]

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_

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.

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.

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

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_.

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_.