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by Helen Caldicott
Posted: 01/05/98
Nuclear reactors were
initially designed to make atomic and hydrogen bombs. Apart from nuclear
war, nuclear power poses the greatest public hazard the world has ever
encountered because of radioactive wastes. Cessation of all forms of
nuclear power is the ultimate form of preventive medicine. The fuel cycle
of nuclear power plants is complex, but not too difficult to understand.
It has many biological and medical implications which must be understood
by the average person in the street as well as by the politicians who make
the most important decisions for society.
In this article, I
describe the fuel cycle step by step, and explain the medical dangers
arising from each step.
1. Mining. Uranium is
the fuel for atomic reactors. When it is mined from the ground it emits a
radioactive gas called radon which is often inhaled into the lungs of
miners where it converts after four days to lead 210 which remains
radioactive for more than 100 years. Radiation in the body is carcinogenic
(cancer-causing). It has been discovered in the U.S. that up to 20% of
uranium miners die of lung cancer over a twelve to forty year period of
mining. Radium can also be swallowed in the dust, absorbed through the
bowel v/all, and laid down in the bone, where later it can induce bone
cancer or leukemia. Gamma radiation (like X rays) is emitted continuously
from the uranium ore. Thus the bodies of uranium miners are exposed,
including their testicles. Radiation damage to chromosomes or genes in the
sperm can induce congenital deformities or genetic disease in the next or
future generations. It could also cause cancer of the testicle.
2. Milling. After the
uranium is mined it is then milled and refined. Thousands of tons of waste
(called tailings) are discarded and left lying in huge heaps on the
ground. The tailings generated in the U.S.A. over the next 24 years may
produce 45 cases of lung cancer in the world per year for tens of
thousands of years. The causative agent is again the gas radon which is
continually emitted from the waste uranium in the tailings. Tailings also
contain radium which is very soluble in water, and in this form is readily
concentrated in plants, animals, fish, and eventually at highest levels,
in human beings, if they eat the contaminated food. Workers at the milling
plant will be exposed as well to gamma radiation as described above.
3. Enrichment and fuel
fabrication. The uranium is then enriched and fabricated into fuel rods
which are transported to the nuclear reactor, and placed in the reactor
core. A typical 1000 megawatt reactor contains 526 bundles and each bundle
consists of 12 rods. The radioactive uranium produces heat by fission
which is utilized to generate electricity. During this process uranium is
converted to many radioactive products which are the "wastes" of nuclear
power.
Once a year one
quarter of the rods are removed from the reactor core because their
generating life has ceased. The rods are both thermally and radioactivity
very hot. If the spent fuel rods are not continually cooled they could
melt down releasing their radioactive elements into the air and water.
Therefore they must be stored on racks in cooling ponds containing water
prior to removal for more permanent storage elsewhere, or possible
reprocessing. They now contain a very large amount of biologically
dangerous radioactive materials including strontium 90, iodine 129, cesium
137 and Plutonium.
4. Reprocessing.
Eventually it is hoped these rods will be transported in caskets to a
reprocessing plant where they will be dissolved in nitric acid. Spent fuel
rods from military reactors in England, U.S., U.S.S.R., and elsewhere are
continually reprocessed for retrieval of plutonium. During reprocessing,
the plutonium is removed from the solution and purified in powdered form
as plutonium dioxide. It is used as either fuel for atomic bombs or fuel
for "breeder nuclear reactors" (reactors which breed plutonium). It is at
this point in the fuel cycle that the greatest dangers arise once the
plutonium is separated* Plutonium is an extremely potent cancer producing
material, appropriately named after Pluto, the God of Hell.
It enters the body by
inhalation of contaminated air, where it is deposited in the lungs.
Because of its potent cancer producing properties the acceptable body dose
has been set at less than I millionth of a gram (an invisible particle).
There is some evidence this level has been set too high. Cancer will not
appear until 15 or 20 years after inhalation. By extrapolation, 1lb of
plutonium, universally dispersed, would be adequate to loll every man,
woman and child on earth. It also has a curious physical property of
igniting spontaneously when exposed to air, thereby producing tiny
aerosolized particles which are dispersed by wind currents and available
for inhalation by humans and animals.
Because plutonium is
the basic material of atomic bombs, it i.e. more valuable than heroin on
the black market, and therefore vulnerable to theft by terrorists,
racketeers, non-nuclear nations and deranged individuals* Reactor grade
plutonium makes inefficient but dirty bombs, 5 kilos of plutonium is
adequate fuel for a nuclear weapon. Man has already made 450 tons of
plutonium.
If the nuclear arms
race continues and nuclear power is not stopped, by the year 2,020 in the
U.S.A. estimates show that the industry could have produced 30,000 tons of
plutonium, most of which will be in powdered form. There will be 100,000
shipments of this material annually on the highways of America. Plutonium
must be transported very carefully, packed in small quantities in separate
containers because 1OIbs. is "critical mass" which means that a
spontaneous atomic explosion could occur if 1Olbs or more were compacted
together in a finite space. One could envisage disastrous consequences if
a truck were to crash, explode and/or discharge some of its deadly
contents.
The most crucial
property of plutonium is half life of 24,400 years, (half life of a
radioactive substance is the period of time for half a given quantify to
decay, and a similar period for half of the remaining radioactivity to
decay, ad infinitum). Therefore radiation from man made plutonium will
exist on earth for at least half a million years. To illustrate the
enormous medical problems arising from the physical properties of
plutonium: if an individual dies of lung cancer engendered by plutonium,
his body will return to dust, but the plutonium lives on to produce cancer
in another human being.
Although it could be
used as "fuel" in breeder reactors, more plutonium will be produced than
will be utilized. So there will be a continual net increase in plutonium
manufactured. The nuclear industry has no idea how to isolate this
plutonium from the environment so it will not damage this, or future
generations.
5. Waste Storage.
There are no permanent safe methods of disposal and storage available at
this point in time. After the plutonium is extracted from the radioactive
waste, very dangerous elements remain, which have no further use and are
pure waste products. This remaining solution contains some plutonium plus
radioactive iodine, strontium 90, cesium 137, as previously mentioned, and
many other highly toxic radio-nuclides. Because it is extremely hot, the
solution must be stored and cooled continuously for years. Currently tanks
with a 30 year lifespan are being used. Every month numerous leaks of
radioactive wastes are reported in the U.S.A. in quantities from several
gallons to 200,000 gallons. When this dangerous fluid leaks, it inevitably
contaminates the local water system and the various elements are taken up
by the food cycle. Radioactive iodine, strontium 90, and cesium 137 are
absorbed by roots of grass and vegetables and are further concentrated in
the flesh and milk of animals when they eat the grass.
Radioactive iodine,
strontium 90 and are concentrated in milk, both human and animal. Cesium
is concentrated in muscle (meat). Like many other isotopes from nuclear
fission these substances are invisible, tasteless and odorless. It is
impossible to know when one is eating or drinking or inhaling radioactive
elements.
6. Meltdown of
reactors due to human or mechanical failure send large quantities of
radioactive isotopes into the atmosphere, and they fall to earth in the
rain as radioactive fallout. In parts of Italy, and presumably Austria,
Germany, Wales, Poland, Russia etc, the concentration of cesium 137 and
other isotopes in the food is as high now as it was several months after
the Chernobyl accident. Because Cesium 157 is radioactive for hundreds of
years, the food in these countries will continue concentrating these
radioactive elements from the soil for hundreds of years. Medical
estimates of post Chernobyl cancer incidence in Europe over the next BO
years, range from 10,000 to I million; 50 years is, of course, an
artificial cutoff. Cancers from Chernobyl will be induced in this
population for hundreds of years.
7. Biological
properties of radioactive waste. All cells of the body have a central
nucleus which contains genes, the basic inherited material which controls
all our characteristics (color of eyes and hair, size, facial
characteristics, enzyme systems etc). Genes are changed by radiation.
Cells and genes which are actively dividing (as in fetuses, babies and
young children) are most susceptible to the effects of radiation,
therefore babies and children are 10-20 times more likely than adults to
develop cancer if exposed. If a gene which controls the rate of cell
division is altered by radiation, the cell may divide in an uncontrolled
fashion to produce cancer and leukemia.
It may take from 5 to
50 years before cancer appears after the cell is exposed to radiation. If
a gene in the sperm or egg is altered by a radioactive particle, the young
may be born either with an inherited disease, or the baby may appear
normal, but will transmit the damaged gene to future generations, to
become manifest in later years. Radioactive iodine in milk is absorbed
through the bowel wall, and migrates in the blood to the thyroid gland in
the neck where it may produce thyroid cancer.
Strontium 90 is also
absorbed through the bowel after being ingested in contaminated milk and
is incorporated in bone because it chemically resembles calcium. This
element may cause osteogenic sarcoma - a highly malignant, lethal bone
tumor, or leukemia, a cancer of the white blood cells. The blood cells are
formed in the bone marrow, and are therefore subjected to the affects of
radiation from strontium 90 in the adjacent bone. Cesium 137 is deposited
in muscles of the body where it can produce malignant changes. Plutonium
is one of the most carcinogenic substances known. It is not absorbed
through the bowel wall, except in infants in the first four weeks of life
when it is ingested in milk. As previously described, infants are
extremely sensitive to the toxic effects of radiation.
The route of entry of
plutonium is by inhalation of contaminated air into the lungs. Small
particles of plutonium are deposited deep in the respiratory passages,
where they remain for years. It is accepted that one millionth of I gram
of plutonium is sufficient to produce lung cancer 151050 years after
initial inhalation of the element. Plutonium is also absorbed from the
lungs into the blood stream where it is carried to the liver (to produce a
very malignant liver cancer), to bone (where like strontium 90, it causes
osteogenic sarcoma and leukemia), and it is selectively taken up from the
circulation by the testes and ovaries where, because of its incredible
gene changing properties, it may cause an increased incidence of deformed
and diseased babies, both now and in future generations.
Plutonium also crosses
the placenta from mothers blood into the blood of the fetus, where it may
kill a cell responsible for development of an organ, e.g. heart, brain,
etc. causing gross deformities to occur in the developing fetus. This
mechanism for production of fetal deformities is called tera-togenesis and
is different from the deformities caused by genetic mutation in the egg or
sperm, because although the basic gene structure of the cells of the fetus
is normal, an important cell in the developing fetus has been killed
leading to a localized deformity. (Similar to the action of the drug
thalidomide).
Massive quantities of
radioactive wastes are being, and will be produced in the future. The safe
storage of wastes is unsolved, and even if there were a present-day
solution, we could not predict a stable society or world for half a
million years; we could not guarantee incorruptible guards, or moral
politicians and we certainly cannot prevent earthquakes, cyclones or even
wars. As waste is leaking now, inevitably it will leak in the future. We
could therefore predict epidemics of cancer and leukemia in children and
young adults, and an increased incidence of inherited disease (there are
3,000 described inherited diseases). It is also inevitable that plutonium
will be stolen and utilized for atomic weapon production (2 tons of
plutonium are presently unaccounted for in the U.S.A.).
It has been claimed
that 80-90% of all cancers may be caused by environmental pollutants. The
incidence of cancer is increasing now and will continue to increase.
Governments spend millions of dollars researching causes of cancer,
leukemia, and inherited disease, but simultaneously spend billions of
dollars in an industry that will directly propagate these diseases.
As a doctor, I appeal
to my fellow medical colleagues to investigate this enormous present and
potential threat to our patients, and to urgently initiate programs of
pro-phylacytic medicine. I also appeal to the Movers and Fathers of the
world to educate themselves about the medical dangers of nuclear power and
to demand from government a safe future for their children, grandchildren
and descendants.
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