Confusion about Fallout
Fallout is essentially the ash and dirt particles caused by large explosions and/or the demolition of large structures, which was graphically displayed by the collapse of the World Trade Centers in 2001. The biological effects of the fallout of dust and microscopic debris on 9/11/2001 were unquestionably horrible. Nuclear weapon’s fallout has the added biological hazard of being intensely radioactive. It’s the instantaneous avalanche of neutrons spewed forth by a nuclear weapon detonation that makes the dispersed dust and debris radioactive. Neutron is the only form of radiation which can cause other materials to become radioactive. The avalanche of neutrons is the main reason why atomic bomb fallout is so highly radioactive. Thus, with nuclear bomb fallout the air is not only fouled by the thick fog of dust, the dust is also significantly radioactive.
The thick dust-fog scenario is virtually impossible for power plant reactor accidents, even for the worst-ever nuclear reactor accident at Chernobyl. The invisible concentrations of microscopic radioactive dust and radioactive gasses from Chernobyl were considerable and resulted in significant short-term biological consequences. But, even the atmospheric release of radioactive material from Chernobyl was many, many times less concentrated than would be the case with nuclear weapon’s fallout. However, this comparison only holds for Chernobyl, a type of nuclear plant only built by the old USSR; a type of plant judged by America to be too dangerous to be considered, soon after World War II. The plants used in the West cannot have Chernobyl-type accidents, and the worst possible invisible radioactive release from a Western nuclear power plant is thousands, if not millions of times less than Chernobyl. The mis-association between weapon’s fallout and Western nuclear reactor accidents makes even less sense than with Chernobyl.
This is also true for Fukushima Daiichi. There were three hydrogen explosions between March 12 ans March 15, 2011, and two of them were caught on camera. In the first two cases, there is considerable dust and debris blown into the air by the blast, and contained some radioactive fission products, but none of the Neutron-induced materials caused by nuclear weapons. Also, the dust clouds “rained out” on the nuclear station’s property which covers more than a square kilometer. As we will soon see, comparing Fukushima’s radioactive atmospheric releases pale in comparison to even the smallest bomb blast.
If not fallout, what is radiation?
In addition to the initial avalanche of neutrons, the resulting fallout contains significant concentrations of Gamma, Alpha and Beta radiation. Gamma radiation is similar to X-rays which can penetrate the body and cause negative ionization inside our bodies when in high concentration. Gammas are essentially tiny clumps of pure energy that have no electrical charge, which allows them to penetrate through our skin and into living tissue.
Alpha and Beta radiations, on the other hand, are actually tiny atomic particles with electrical charges, which makes their penetrating power very low. An Alpha particle is the nucleus of a Helium atom, minus the two electrons normally spinning about the inert element. The Alpha’s adverse biological effect is the stripping of electrons from the first atoms it comes close to, ionizing the stripped atoms. Then, the Alpha becomes non-radioactive Helium, which is biologically harmless. Alphas are very, very active, and because of this they cannot penetrate anything as sheer as a thin sheet of tissue paper. Our outer layer of dead skin is an impregnable shield against Alpha radiation.
The Beta particle is actually a free, highly-energized electron. When Betas come in contact with anything as thin as hevy aluminum foil, they are completely “attenuated” (de-energized) and immediately absorbed by the available electron shells of surrounding atoms. Low energy Betas can be completely attenuated by generic cellophane. Because betas cannot penetrate very well, our skin is a very good shield against Beta radiation. It should be noted that the inert gasses, Krypton and Xenon, only release Alpha and Beta radiations. These are the two most common radioactive elements released during a nuclear plant’s routine operation. Because they are chemically inert, these two elements cannot be absorbed into and retained by the body. They are essentially an innocuous and harmless “external” exposure source, but not a damaging “internal” exposure source.
However, if radioactive dust emitting Alphas and Betas is breathed into our lungs, or swallowed, it stays there. When and if this happens, the radioactive particles are released directly into living tissue and cellular damage can occur, although cellular and DNA repair mechanisms are extremely good at fixing the damage at low exposure levels. A Beta is just as potentially damaging as Gamma radiation when absorbed by living tissue. What’s more, Alpha ionization can be twenty times more damaging to living tissue than Gamma. In other words, it’s not only the choking, smothering dust in nuclear bomb fallout we should concern ourselves with, it’s the internally released Betas and Alphas from the ingested dust that can cause additional biological harm. With routine power plant radiation releases, however, the inert chemistry of the radioactive elements that are released (without the dust made by a bomb) makes exposure levels vanishingly small.
Now, let’s turn to the radioactive material we can be exposed to from civilian reactors. First, only those people downwind of the reactor ever find themselves in the path of the reactor plant’s atmospheric effluvia (plume). This point needs to be emphasized. Even in a worst case meltdown from a Western civilian reactor, only those people living downwind will be possibly subjected to the invisible plume. People living upwind or otherwise beyond the borders of the plume will not be exposed. The release of radioactive material will not spread out in all directions at the same time, as would be the case with a nuclear explosion. Reactor plant releases are carried by the wind.
Next, nearly all the radioactive releases from a civilian reactor during routine operation, and the most probable radioactive elements from accidents, are Beta and Alpha emitters. There is no Neutron radiation at all. There are precious few Gamma sources to speak of, and only potentially released during a severe accident. Thus, the two most damaging forms of radiation from bombs and fallout, Neutron and Gamma, are not what we can realistically expect from power plant reactors.
What about all the Iodine from a nuclear accident?
There has been considerable press about the possible release of radioactive Iodine from worst case power plant reactor accidents, which could concentrate in the thyroid gland. The catastrophe at Chernobyl exacerbated this notion, although such a high Iodine release seems unique to the Chernobyl-type reactor alone. Regardless, Thyroid-blocking medication is now routinely distributed to everyone living within 10 miles of an American civilian nuclear reactor…just in case a gargantuan burst of radioactive Iodine is somehow belched from the plant‘s ventilation system. This is a practice to prevent thyroid irradiation should there be a worst case accident, and a highly unlikely chain of associated safety air cleanup systems also fail, and the fuel cell is massively damaged in order to release the Iodine, and the ruptured fuel particles finds their way out of the many inches thick, solid steel vessel, and, the released Iodine makes it out of the massive steel and concrete barriers surrounding the reactor itself, and is carried by the wind to populated areas. Highly unlikely from a non-Chernobyl-type reactor? Yes. Absolutely impossible? No.
The three damaged units at F. Daiichi released significant amounts of radioactive Iodine. At least, that is what it might seem like when we see the number of Becquerels that were expunged; approximately a million-million-million Becquerels, to be precise. This sounds like something extremely hazardous because of the huge numbers involved. However, this is about 10% of the total Iodine released by Chernobyl. Second, at least half of it was blown out to sea during the releases. Third, the Japanese government mandated strict evacuation and/or shetering orders early-on in the accident – in fact this occurred out to 20 kilometers from F. Daiichi on the first day of the crisis, which was three days before any releases went inland. Finally, All Iodine that was deposited on land decayed away to nothing in less than three months due to its 8-day half-life. Thus, comparing Fukushima’s Iodine releases, in fact the releases of any Fukushima isotopes, to Chernobyl is informative but should not be used to mislead people into thinking we have another Chernobyl, or worse, on our hands.
There has been only one reactor accident that released some 10% of the radioactive material found in the fission product matrix of its severely damaged reactor fuel; Chernobyl…Fukushima may have releasesed a tenth of what was spawned by Chernobyl. While there was no Neutron-Gamma burst at Chernobyl like we would have with a bomb, and the amount of subsequent radioactive material released was but a fraction of what would come from nuclear bomb fallout, the accident itself bears a bit more mention here. In addition to the Alpha and Beta-emitting inert gassses, considerable Iodine was released, along with dozens of other radioactive elements like Cesium, Barium, and Strontium. The Cesium is considered to be the most hazardous of the isotopes that escaped into the atmosphere because of its lasting existence in the surrounding soil and water within 30 kilometers and downwind of the accident itself. Regardless, after more than 25 years following the accident at Chernobyl and the initial spawn of some 4,000 child-thyroid cancers, more than 99% of those cancers have been cured. In addition, no long-term health effects have occurred. (see “Chernobyl Disaster” page)
By comparison with Chernobyl, the amount of radioactive debris emitting Alpha and Beta radiation potentially resulting from the worst-possible accident at a modern, safety-system protected Western reactor is lierally microscopic. The entire radioactive release from Three Mile Island resulted in an exposure to the nearest members of the public living downwind which was less than 10% of what they received from natural background radiation that same year. People 50 miles away got much less than 1% of their annual natural radiation dose. Thirty years of subsequent detailed medical and health records reveal that the biological impact of TMI on the public has been zero. Further, Three Mile Island‘s accident may well have been the worst possible accident a fully-safe-guarded Western civilian reactor could experience. (More on this in the TMI page)
The bottom line is this; the public’s radiation exposure from Western reactors, and their worst-possible accidents, in no way corresponds to what the affected public would experience from fallout due to a nuclear explosion. It’s worse than comparing apples to oranges. It’s the equivalent of saying apples are oranges.
1. The radioactive relesases from nuclear power plants should not be called “fallout”.
2. The most damaging types of radiation from bomb fallout are not the types released from power plant reactors.
3. Our skin is an excellent shield against nearly all radioactive releases from the operation of a power plant reactor.
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http://www.nationalterroralert.com/nuclear/; Feb. 17, 2010
- Talbot, Youk, McHugh-Pemu, and Zborowski; Long-Term Follow-Up of the Residents of the Three Mile Island Accident Area: 1979-1998; Environmental Health Perspectives;
- Chernobyl Accident; World Nuclear Association;
http://www.world-nuclear.org/info/chernobyl/inf07.html; November, 2009
- Chernobyl; Hyperphysics; Department of Physics and Astronomy, Georgia State University;