Since the terrorist attacks of September 11, Americans have had to learn to discriminate between real and imagined risks in many areas. When it comes to domestic nuclear terrorism—a subject that has been touched recently by highly speculative journalism—making that distinction requires knowing some nuclear fundamentals. Based on science, what should Americans worry about?
Is radiation always dangerous? How do we protect ourselves? Could terrorists unleash a Chernobyl on our soil? Could nuclear waste dumps or power plants be transformed into atomic weapons? Could they steal an American nuclear weapon and detonate it? Some findings may remain undisclosed for security reasons; others may be made public—soon, one hopes. Meanwhile, here are some basics. Hahn Broadband Edited by Robert W. Crandall and James H.
Alleman Radioactive materials contain unstable atoms, radionuclides, that emit excess energy as radiation, invisible but detectable by instrument. Some atoms lose their energy rapidly; others remain dangerous for thousands, even millions of years.
Certain forms of radiation are more hazardous to humans, depending on the type of particles emitted. The United Nations Scientific Committee on the Effects of Atomic Radiation UNSCEAR , composed of scientists and consultants from 21 nations, provides comprehensive evaluations on sources and effects of radiation as the scientific basis for estimating health risk. It recently listed annual average exposures per person worldwide.
G Gwyneth Cravens. Natural background radiation: millirem worldwide millirem in the United States. Cosmic rays, sunlight, rocks, soil, radon, water, and even the human body are radioactive—blood and bones contain radionuclides. Exposure is higher in certain locations and occupations than in others airline flight personnel receive greater than average lifetime doses of cosmic radiation.
Diagnostic medical radiation: 40 millirem 60 millirem in the United States. This is the largest source of manmade radiation affecting humans. Other common manmade sources include mining residues, microwave ovens, televisions, smoke detectors, and cigarette smoke—a pack and a half a day equals four daily chest x-rays. Coal combustion: 2 millirem. Radioactive fly ash, a coal byproduct used in building and paving materials, contributes an additional dose.
Coal pollutants are estimated to cause about 15, premature deaths annually in the United States. Nuclear power: 0. For radiation to begin to damage DNA enough to produce noticeable health effects, exposure must dramatically increase—to about 20 rem, or 20, millirem.
Above rem, or , millirem, diseases manifest. Whether low-dosage radiation below a certain threshold poses no danger and may in fact be essential to organisms is controversial the Department of Energy began the human genome project to help determine if such a threshold exists. If exposure is not too intense or prolonged, cells can usually repair themselves. Radiation is used widely to treat and to research illnesses.
The horrible—and preventable—reactor explosion at Chernobyl caused fatalities and suffering among the local population but increased the overall background radiation level by a factor of only 0. The severest casualties occurred among plant workers and firemen, two of whom died from scalding. Another suffered acute radiation sickness. Twenty-eight of those victims died within three months; 13 succumbed later. The rest survived. Among civilians in surrounding communities, UNSCEAR found 1, cases of thyroid cancer, mostly in children, and predicted more would develop.
Thyroid cancer could have been avoided, however, had the entire population surrounding Chernobyl been promptly given potassium iodide, which blocks the uptake by the thyroid of radio-iodine, a radionuclide produced by reactors. Fourteen years after the accident, no other evidence of a major health effect attributable to radiation exposure had been found.
The risk of leukemia, one of the main concerns owing to its short latency time, does not appear to be elevated, not even among the recovery operation workers. Although those most highly exposed individuals are at an increased risk of radiation-associated effects, the great majority of the population are not likely to experience serious health consequences from radiation from the Chernobyl accident.
Better management of the emergency, including adequate dissemination of facts, probably could have prevented much of this psychic trauma.
Risk perception tends to be skewed by unexpected, dramatic events—a quirk of human nature exploited by terrorists. More severe risks almost always lurk in everyday life: cardiovascular disease about 2,, U. That other accident-related cancers may eventually appear around Chernobyl is possible but unlikely, given results of long-term surveys of the approximately 85, survivors of the bombs exploded over Hiroshima and Nagasaki in Despite the far higher dosages of radiation to which these victims were exposed, recent data cited by Fred Mettler, U.
Normally about one in three humans gets cancer. A few years ago, after much debate, the U. Nuclear Regulatory Commission offered free emergency contingency supplies of potassium iodide to the 31 states with reactors, but most declined. Delay from the Food and Drug Administration regarding approval of the antidote, as well as opposition to it at the county level, created further obstacles.
After September 11, communities and politicians expressed indignation that this inexpensive drug had not been stockpiled. This measure would supplement sheltering and evacuation, the usual protective measures. Could any of the nuclear reactors in the United States be turned into a bomb?
The laws of physics preclude it. In a nuclear weapon, radioactive atoms are packed densely enough within a small chamber to initiate an instantaneous explosive chain reaction.
In Britain, the civil nuclear power programme was deliberately used as a cover for military activities. For example, the atomic weapons facilities at Aldermaston and Burghfield in Berkshire, where British nuclear weapons are built and serviced, are still deleted from Ordnance Survey maps, leaving blank spaces.
The newsreel commentary described how it would produce cheap and clean nuclear energy for everyone. This was untrue. Calder Hall was not a civil power station. It was built primarily to produce plutonium for nuclear weapons. The electricity it produced was a by-product to power the rest of the site. In , a major fire occurred at Windscale nuclear site what is now known as Sellafield.
The amount was not hazardous and in fact it was carried out to sea by the wind. When, in , Greenpeace divers discovered highly radioactive waste being discharged into the sea through a pipeline at Sellafield and tried to block it, British Nuclear Fuels Ltd BNFL , who then operated the site, repeatedly took Greenpeace to the High Court to try to stop them and to sequestrate its assets.
The first generation of British Magnox nuclear power stations were all secretly designed with the dual purpose of plutonium and electricity production in mind. Some people think that because plutonium is no longer needed by the UK to make weapons as it already has huge stocks of weapons grade plutonium, there no longer is any connection between nuclear weapons and nuclear energy. This is incorrect: they remain inextricably linked. For example:. The development of both the nuclear weapons and nuclear power industries is mutually beneficial.
This could explain why Prime Minister Theresa May continues to support subsidising a project which looks set to cost the taxpayer billions. Radioactive nuclear waste is produced by all nuclear activities. For example, uranium mining produces a great deal of waste in the form of ore spoil like all mining. Since uranium is radioactive, so are its ore wastes. So also are all the processes of refining the ore, enriching the uranium, turning it into fuel for reactors, transportation, burning it in nuclear power stations, processing the used fuel, and its handling and storage.
They all create more nuclear waste. The reason is that everything that comes into contact with radioactive materials, including the containers in which they are stored or moved and even the buildings in which they are handled, become contaminated with radioactivity or are activated by radiation. All radioactive waste is dangerous to human life as exposure to it can cause leukaemia and other cancers. It is usually categorised as low, intermediate or high-level waste. As the radioactivity level increases, so does the danger.
Extremely high levels of radioactivity can kill anyone coming into contact with it — or just getting too close to it — within a matter of days or weeks. Radioactive materials slowly lose their radioactivity and so can become in theory safe to handle but in most cases this is a very slow process. Plutonium, for instance, has a half-life of over 24, years which means it will remain lethal for over , years.
Other radio-isotopes remain radioactive for millions or even billions of years. The safe, long-term storage of nuclear waste is a problem that is reaching crisis point for both the civil nuclear industry and for the military. During the Cold War years of the s and s, the development of the British atomic bomb was seen as a matter of urgency.
Dealing with the mess caused by the production, operating and even testing of nuclear weapons was something to be worried about later, if at all. For example, the Ministry of Defence does not really have a proper solution for dealing with the highly radioactive hulls of decommissioned nuclear submarines, apart from storing them for many decades. As a result, 19 nuclear-powered retired submarines are still waiting to be dismantled, with more expected each year.
Yet Britain goes on building these submarines. This callous disregard for the future has spilled over to the nuclear power industry. For example, at Dounreay, in the north of Scotland, nuclear waste and scrap from the experimental reactor and reprocessing plants were simply tipped down a disused shaft for over 20 years.
No proper records of what was dumped were kept and eventually, in , an explosion showered the area with radioactive debris. The fireball produces temperatures up to millions of degrees, shock waves similar to a large earthquake, flashes similar to lightning and intense radiation. The mushroom cloud carries radioactive materials from the bomb into the air. When the cloud settles down, dust and particles containing radioactive materials fall back to earth.
This is called fallout. Fallout can be carried by the wind and can contaminate the air, soil, food and water. An accident at a nuclear power plant would not produce a fireball or mushroom cloud like a nuclear blast. However, it could release radioactive materials into the air, though this would be at a much lower level than a nuclear bomb blast.
More information on nuclear power plant accidents is available on a separate fact sheet. The health effects depend on the distance from the blast. Injury or death may result from the blast itself or from flying debris. Those who look directly at the blast could experience temporary blindness or severe eye damage. People near the blast site would be exposed to high levels of radiation causing severe skin burns, shock and death within minutes to days.
People farther away may be exposed to lower doses of radiation from the blast or by breathing air, eating food or drinking water that is contaminated with fallout. Exposure to radiation increases the chance of developing cancer and other health problems years later. If you are near the blast when it occurs: Turn away and close and cover your eyes. Drop to the ground face down and place your hands under your body. Remain flat until the heat and shock waves have passed.
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