February 1972 Popular Electronics
Table of Contents
Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
and the list goes on. These and other radioisotopes associated with nuclear material
are the result of explosions, medical treatments, laboratory experiments, or in some
cases naturally occurring deposits. Regardless of the source, most people, including
me, cringe at the thought of being exposed to the insidious effects of the
cell-altering energy they possess.
radiation is the dangerous type of radiation due to its ability to dislodge
electrons from atoms, and in the process forming cancerous cell mutations or killing
the cells altogether. Researchers in the early days of radiation discovery
experienced sometimes gruesome maladies as a result of the handling isotopes. Some
knowingly subjected themselves to harmful doses in order to further science. Although
I couldn't find it now in a search, I recall reading about and seeing a photo of a
doctor who purposely exposed one of his own hands to x-rays to determine energy
levels hazardous to human skin tissue.
Nuclear Radiation ... Insidious Polluter
Electronics helps monitor and control contamination
you can't see, hear, taste, smell, or feel
By Forest H. Belt
Most people relaxed and quit worrying about fallout and the "bomb" nearly a decade
ago. The Limited Test Ban Treaty (June 1963) ended atmospheric testing of nuclear weapons.
Only Red China and France have exploded bombs since then with predictable radioactive
clouds wafting across continent and ocean.
Two-layer plastic radiation suits reduce exposure danger for workers
entering contaminated area. Umbilical tube carries fresh air and communication wiring.
On leaving area, worker simply shucks the outer suit. (Photo: US Atomic Energy Comm.
In spite of the "now" issues, the specter of harm from nuclear radiation is still
with us. Tests of nuclear explosives continue, although most are performed underground.
Nuclear power plants dot the nation. The result is that chances of radiation pollution
Some scientific authorities say that we relaxed under false assurances. The Atomic
Energy Commission keeps telling us that none of today's uses of nuclear energy present
any significant danger. Yet, the evidence keeps piling up that potential radiation danger
lurks in peaceful uses of nuclear power.
We have accumulated more knowledge of the Hiroshima/Nagasaki survivors and their descendants.
Some genetic consequences were already acknowledged. We know now that even the grandchildren
of the survivors are affected. Abnormalities include birth defects, stillbirths, and
heredity-related diseases. Lately, cancers began appearing in the bomb victims themselves,
and at a rate greater than the national average for all of Japan. And the incidence of
the disease is roughly proportional to the amount of radiation the survivors received
during the five-year period following the bombings. Accelerated aging is noticeable in
some victims who were exposed to fallout when they were very young.
Consequences like these, turning up so long after exposure, require that we reevaluate
our thinking. What illnesses will workers near radioactivity contract? What effects will
they have on their offspring in the future.
Proponents of mare nuclear power put forth a threshold theory which assumes that there
is some small radiation dosage below which effects are zero. This concept is based mainly
an the lack of any immediate symptoms when the radiation dose is very low. But evidence
gathers far the linear theory, that radiation-related diseases and genetic aberrations
increase in proportion to the radiation one accumulates, even to the most minute dosage.
This means that radiation might have a cumulative effect. It is possible then that future
generations well may carry the burden of any radiation carelessness now.
Nuclear fission occurs when a high-speed neutron splits nucleus of
uranium or plutonium. Tremendous energy is released and other neutrons are knocked loose.
If released energy is sufficient, chain reaction can occur.
Radioactive Materials. If neutrons forced out of atoms as a result
of nuclear reaction reach the air, they can mix with nitrogen atoms and form carbon 14.
This radioactive nuclide has an extremely long life and can be very dangerous to man.
Obviously, then, in employing nuclear reactors for peacetime applications, neutron escapes
must be prevented.
The decay of uranium-235 also forms variants called isotopes. If the isotopes get
out of a reactor, they can carry radiation to us in various ways, mainly by concentrating
in our food and water.
Strantium-90, for example, settles to earth where grass absorbs and concentrates it
in its blades. Cows grazing on the contaminated grass increase the concentration in their
milk. Anyone who drinks the milk gets a hefty dose of the beta rays given off by the
isotope. Other nuclides collect in other foods, animals and fish. Many of these nuclides,
in addition to giving off beta rays, are contaminated with alpha or gamma radiation.
Beta radiation is not strong. Skin, muscle, and other tissue help to block it when
the body is externally exposed. Taken internally, however, strantium-90 settles in bone
and muscle where beta rays freely emanate for more than 25 years. This is an open invitation
to leukemia and cancer.
Editor's Note: There are many benefits to be derived from the peaceful
use of nuclear energy, especially in the fields of power generation and medicine. Although
this article points out the dangers involved, we can take advantage of the benefits and
minimize the hazards by enlisting the aid of electronics and other safeguards in control
and monitoring. Those involved with the applications of nuclear energy are well aware
of the problems in working with such a potent force. Hence, safe operating practices
are observed to keep all hazards to an absolute minimum.
The isotope cesium-137 also goes to muscles and bones. Beta and gamma rays from it
endure beyond the nuclide's 33-year half life. (Note: Radionuclides are considered to
be ineffective after half their atoms have decayed, although some of their rays remain
potent for a longer time.) Gamma rays are intensely more penetrating than are beta rays.
They can destroy body cells from relatively great distances.
Iodine-131 gathers in thyroid and salivary glands. This isotope has a half-life of
only eight days, but gamma and beta rays from it are energetic. They damage sensitive
throat cells and trigger thyroid cancer.
Plutonium-239 is the most hazardous byproduct of uranium-235 fission. Its half life
is 24,100 years. It is a deadly source of alpha and gamma rays that are so powerful that
they still produce lung cancers when the isotope has aged 200,000 years! Exposure to
fresh plutonium-239, even briefly, multiplies cancer susceptibility a thousand-fold.
Ionizing radiation produced by atomic decay attacks body cells. Radioactive particles
rip electrons out of atoms in cells. Sometimes the shock kills the cell, sometimes it
merely fouls up operation. Damaging a body cell sets the stage for cancer and other diseases.
Chromosome damage in the reproductive cells leaves consequences that may linger for generations.
Some cell damage self heals. Some damage is irreparable. The body often replaces dead
cells, which leads some experts to contend that there is a threshold level below which
radiation will do no somatic or genetic damage. True, below certain levels no immediate
clinical symptoms appear, but radiation doses accumulate and eventually produce effects
that are noticeable.
Nuclear test blast in Nevada near Los Alamos lab had nearby tower
that held electronic instruments to measure seismic shock, radiation, etc. (Photo Los
Alamos Scientific Lab)
Typical Radiation Doses. We cannot see, hear, taste, or feel radiation,
but it is always around us. We get yearly background dosages of about 125 millirads -
more if we live at high altitudes. (A rad is a measure of radiation standing for Radiation
Absorbed Dose and is roughly equal to a Roentgen, or rem, which is a technical unit of
radiation. The rad is abbreviated as the letter "r.")
An average of 50 mr of annual background dosage is due to cosmic radiation from high-energy
protons originating in outer space. Another 50 mr or so comes from potassium-40, thorium,
and uranium in the air, soil, and buildings. And about 25 mr comes from inside our bodies.
We ingest through breathing, eating, and drinking traces of thorium, potassium-40, carbon-14,
and tritium; and there is no way to avoid them.
Whenever we have an X-ray picture taken, we get a dose of radiation. The younger we
are, the more damage X-radiation is likely to cause. A study by Dr. Alice Stewart of
Great Britain - confirmed by Dr. Brian MacMahon of Harvard - relates X-rays during pregnancy
to a rise of cancer and leukemia in children age 10 years and younger.
X-rays are, nevertheless, beneficial diagnostic tools in medicine. The American College
of Radiology, however, advocates reduction of per-photo dosage; this will help. X-rays,
cobalt-60, and other radioactive isotopes also have high therapeutic value. But in spite
of their obvious beneficial qualities, they remain sources of hazardous radiation.
Safety guidelines have been set up by the Atomic Energy Commission, with aid provided
by the Federal Radiation Council, the National Committee on Radiation Protection and
Measurement, and the International Commission on Radiological Protection. The guideline
doses are represented as "safe" exposures. But in light of recent data and experience,
some scientists in the nuclear and health fields dispute their safety.
Articulated mechanical arms and hands let chemist work with radiopharmaceuticals
in safety behind concrete wall and sheets of heavily leaded glass. (Photo: USAEC)
The guidelines suggest that the average dosage for the population at large be less
than 170 mr/yr, not counting natural background radiation. Anyone person should receive
no more than 500 mr/yr, say the guidelines. Individuals in radiation-associated jobs
are permitted an "acceptable" dosage of 5000 mr/yr - 40 times the background level.
Medical Physicists John W. Gofman and Arthur R. Tamplin of the Lawrence Radiation
Laboratory in California make a strong case that even 170 mr/yr can induce an extra 32,000
cancer (plus leukemia) cases annually, representing a 10 percent rise over the usual
average. Also, genetic effects might add 150,000 deaths and even more deformities and
Naturally, nuclear industries take elaborate precautions to maintain exposure below
the AEC maximum. Shielding and special suits are used to block nuclear rays. Remote control
handling keeps operators away from critical materials. Instruments monitor radiation
levels where contamination might exist or develop. Some cities, like New York, monitor
nuclear radiation level constantly. Film badges check the daily and weekly rad dosages
of workers who risk exposure. But for the ordinary citizen, the only real safety lies
Fission vs. Fusion Power. There is currently a big controversy raging
with reference to nuclear-electric power plants. The plants may look clean and harmless,
but their reactors are sources of radioactive discharges into the surrounding environment.
There is also the possibility that accidents caused by man or nature (freak tornadoes,
floods, earthquakes, etc.) could spread radiation for miles.
Hauling and storing nuclear leftovers also present pollution hazards. This particular
problem worries Kansans around the Lyons salt mines where nuclear waste is being dumped.
And there are dangers near plants where reactor fuels are processed.
Many worried citizens want no more nuclear power plants built unless they release
no contaminants at all. California, Oregon, Minnesota, and New York City have even legislated
moratoriums that are still in the courts.
Meanwhile, power companies state that we must convert to nuclear power because we
have enough fossil fuel to carry us through only 200 more years. This is a poor argument
considering that we have only 75 years' worth of uranium at our present rate of consumption.
Emergency radiation team members at AEC's Hanford Works show how Geiger
and scintillation counters are used to measure radioactive contamination should it get
out of control of users of radioactive isotopes. (Photo: Hanford Oregon, Atomic Products
Fast-breeder reactors can develop large quantities of a plutonium-239 byproduct that
can be fissioned into other reactors. But plutonium is formidable to store and transport.
Fusion, the thermonuclear reaction used in the hydrogen bomb, offers an alternative.
Its deuterium fuel, a heavy isotope of hydrogen, is abundant and relatively inexpensive.
A little generates a lot of power, and known accessible reserves could last us 50,000
years. But most promising, for equivalent energy released, a fusion reaction produces
about a million times less radioactivity than does a fission reaction.
The problem is that fusion reaction is not easy to produce or control. We have machines
that can take care of both jobs on a limited basis, but none is ready for commercial
exploitation, nor are they likely to be for a decade or more.
The chief radiation danger from fusion is high-energy neutrons. As already stated,
neutrons form carbon-14 in air. Also, neutrons wear out the protective vanadium allays
used in reactors.
Tritium, produced within the reactor, has a half life of 12.5 years and emits strong
beta rays. So, it must be kept from contaminating air or water.
A deuterium-helium thermo nuclear reaction can make electricity directly. The method
is being worked out at the Lawrence Radiation Laboratory. A plasma is confined in a straight
tube called a "magnetic mirror machine." The reaction spews electrons out of the tube
into an expansion chamber. Collector electrodes gather positive charges and a charge
separator picks up the electrons. Output terminals feed the direct current to whatever
load is provided.
Fusion reaction is a relatively "clean" method of generating power, but mechanical
problems in employing it on a universal scale are still far from resolved. Consequently,
we are stuck with fission reactors to produce energy; so, we are also stuck with the
dangers they present - unless legislation eliminates the use of nuclear power plants
A Growing Tide. We still test nuclear weapons in spite of the April
1970 Treaty an Nonproliferation of Nuclear Weapons and our present Strategic Arms Limitation
Talks. Controversial underground tests continue in Colorado and Nevada. And, in early
November, a giant 5-megaton thermonuclear device for our anti-ballistic missiles was
tested a mile beneath the ground on Amchitka Island. Neither earthquakes nor tidal waves
were triggered and the AEC states that no radiation escaped into the atmosphere.
Missile submarines such as the USS George Washington and ships like the carrier USS
Enterprise carry fusion reactors for propulsion, No reactor is entirely "clean": so,
only "safe" doses of radiation reach the men who run our nuclear fleet.
Portable radiological survey instruments built by private industry
for Oak Ridge National Laboratory. Individual meters are for neutrons, beta and gamma
rays, and alpha particles. (Photo: Oak Ridge National Laboratory)
The National Aeronautics and Space Administration has a nuclear-powered rocket called
NERVA (Nuclear Engine for Rocket Vehicle Application). Nuclear propulsion could considerably
shorten trip time between earth and moon. Astronauts already get nearly 1000 mr of radiation
exposure on an Apollo trip, mostly from traversing the Van Allen radiation belts. A quicker
trip through the belts may balance out the effects of radiation from the engine.
A new nuclear-electric racket develops only a few pounds of thrust. However, it operates
continuously over a long period of time; so, deep-space vehicles could build up extreme
velocities aver the long haul. Systems for Nuclear Auxiliary Power, or SNAP, thermoelectric
generators already make electricity for scientific experiments on the moon. Larger versions
might serve earth needs. Our SNAP-27 uses plutonium-239, but scientists are working on
The Big Ditch. Massive nuclear explosives offer engineering promise.
But radiation problems hamper the use of such power. A detonation in 1967, called "Gasbuggy,"
attempted to boost gas output of a well in New Mexico. Rulison, a similar project in
Colorado, took place in 1969. Unfortunately, the gas released is dangerous; no matter
whether fission or fusion explosives were used, tritium or krypton-85 in the gas exposes
customers to radiation. Decontamination is too costly or impassible. Tests in oil fields
also flapped; the blasts left too much tritium in the ail output.
The most exciting excavation proposal to date is the large sea-level canal to be cut
across Central America to replace the soon-outmoded Panama Canal. Thermonuclear blasts
appear to be the only economical means for such difficult digging chores - but not without
Nuclear tests have been detonated above-ground very little since 1963. Engineers are
not sure how to deploy the explosives to achieve the desired results. Seismic shock could
tear up nearby towns, and the acoustic shock wave has its own dangers. But worse still
is the fact that scientists simply cannot produce a radiation-free nuclear explosion.
The cleanest fusion explosives still dump neutrons and tritium into the atmosphere.
The new canal is therefore stymied. So are other excavation projects. Truly safe peacetime
nuclear technology awaits fission or fusion that does not cause radiation pollution.
Posted May 22, 2018