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Medical Implications Of Nuclear Power by Dr. Helen Caldicott 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 utilised 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, caesium 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 1 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, 1 lb. of plutonium, universally dispersed, would be adequate to kill every man, woman and child on earth. It also has a curious physical property of igniting spontaneously when exposed to air, thereby producing tiny aerosolised 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 ie 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 10 lbs. is “critical mass” which means that a spontaneous atomic explosion could occur if 10 lbs. 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 utilised 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, caesium 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 odourless. It is impossible to know when one is eating or drinking or inhaling radioactive elements. 6. Meltdown 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 1 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 (colour 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 leukaemia. 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 leukaemia, 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. Caesium 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 1 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 leukaemia), 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 leukaemia 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, leukaemia, 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 Mothers 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. |
