Anyone who has the lightest familiarity with nuclear power knows that it is impossible to steal fuel from an operating reactor. Even assuming a terrorist knew how to shut it down, there is still the problem of very high level radiation within the reactor core that would be fatal in a matter of minutes for anyone who attempted to break in. (Our brave terrorist - pardon the oxymoron - would find this a very unpleasant way to enter paradise.)
The same goes for hijacking the spent-fuel truck or train on the way to the reprocessing plant. After storage for at least five years at the power plant site, the "spent" fuel is still highly radioactive and thermally quite hot. Hijacking 44,000-pound fuel containers - designed to smash into a concrete wall at 60 mph or fall onto a spike from thirty feet without rupturing - is a bit difficult to do surreptitiously.
This leaves us with raiding the reprocessing plant (bad idea) or stealing the fuel from shipments to the power plant (best bet). Assuming that the militants can make off with a huge truck, monitored as all valuable shipments are with global positioning electronics and probably guarded, and that no one notices this cargo with the huge radioactive symbols all over it, the hijackers must plan ahead to make sure their plutonium reclamation plant is near by. Typically the price tag on such a facility is in the hundreds of millions, or billions of dollars - and, of course, they've got to hide this construction from the prying eyes of swarms of government inspectors looking for something to inspect... or, even more difficult to avoid, the office-supply salesmen in the four surrounding counties.
Assuming the truck is hijacked and taken to the secret $100 million facility, the problems are just starting for our ill-intentioned thieves. Now they must cut up the fuel assemblies and dissolve them in nitric acid. After that, the chemical processes to separate the plutonium from the uranium are devilishly tricky - in part because an almost-certainly fatal criticality accident can occur quite easily when the plutonium is in a liquid form. But let's assume that our "clever" terrorists are successful in refining out the plutonium and have shaped it for a bomb. Two big problems:
The first is obtaining the explosive charges necessary to "implode" a sphere of plutonium in on itself - essentially taking a hollow globe and compressing it down to a golf or tennis-ball-sized solid... well, almost solid. Regular explosive won't work, as the charge must have different characteristics as it "burns" to maintain the shape of the shock wave that is doing the compressing. Then there is the matter of the initiator, or trigger - the device that produces a stream of neutrons to start the reaction inside a one-tenth microsecond envelope when they are needed. This was considered by the Manhattan Project team (approximately 130,000 personnel, including arguably the best physicists and engineers in the world) as one of the most difficult items to design. Polonium 210 and beryllium must be mixed thoroughly - but this must occur within the aforementioned 0.0000001-second time frame. But let's suppose they are able to do all this. Sorry, still no cigar.
For you see, problem two, the plutonium they liberated from the Imperialist Yankee Running Dogs is not suitable for making a decent bomb. Since BWR and PWR reactors "burn" fuel slowly, Pu239 is created not only from the U238, but also from the Pu240 isotope. While not a fissionable isotope (which wouldn't make much difference in small concentrations), it is a spontaneous neutron emitter, which bodes ill for aspiring bomb makers. Even a very small amount of Pu240 is sufficient to throw off the timing of the necessary bomb reaction by starting it before the implosion is complete - causing the bomb to fizzle. Oh, you'll get an explosion of sorts - perhaps sufficient to flatten a city block or two - but not as awful as what you could do with ammonium nitrate and a little fuel oil, a la Oklahoma City. (The 1947 Texas City blast - where 512 were killed - was also a fertilizer explosion, which didn't require any plutonium at all.)
Terrorists are, in my mind, among the most despicable of humankind. But this isn't to say they are stupid. If they want to kill people and spread fear, there are a lot of easier ways to do this, and they know it. Poisoning the water supply, blasting a hole in a dam, setting oil storage facilities afire when the wind is blowing toward a heavily populated area - the list goes on and on. But building a dud bomb from hijacked plutonium isn't one of them.
Showing posts with label Manhattan Project. Show all posts
Showing posts with label Manhattan Project. Show all posts
Tuesday, April 12, 2016
Sunday, April 3, 2016
The Cornucopia of Nuclear Power
You will remember from chapter 21 that we have two neutrons, on average, emitted whenever a U235 atom undergoes fission - or "splitting." One of these is necessary to fission another atom to keep the chain reaction going. But what happens to all of those second neutrons? Some of them, as mentioned, are absorbed by the structure of the reactor or by the control rods, which slide in and out of the reactor to keep the reaction at - or just very slightly above - the critical point. But others smash into, and are captured by, the plentiful U238 atoms that make up from 95% to 96.5% of the fuel rod contents. When this happens, a truly miraculous thing takes place: This practically worthless material is transformed into one of the most concentrated sources of energy on Earth - or in the universe for that matter - plutonium 239, and element so evil that it was named for the god of the underworld. (Not really, but that's what some would have you believe.) [Plutonium was named in honor of the discovery of the planet Pluto, just as neptunium and uranium were named for Neptune and Uranus.]
This happens in every one of the world's 500 power reactors, plus thousands of research reactors, every day they are in operation. In fact, a sizable fraction (up to about 30%) of electrical energy generated by a power plant comes from this plutonium, which arises as a natural consequence of the uranium fission reaction - without any effort on our part - and supplements the scarce U235 fuel.
Some reactors, however, are designed to intentionally make plutonium. If it is to be used in bombs, it is normally made in a reactor with another modulator - such as the carbon-modulated reactor at Chernobyl. A reactor designed specifically to make only fuel-grade plutonium is called a breeder reactor, since new fuel is "bred" from an almost worthless byproduct of the refining cycle. [Breeder technology seems to be on hold for a couple of reasons: (1) in the prevailing anti-nuclear climate, few entrepreneurs or speculators are willing to make investments in nuclear power for fear of laws that can make their investment instantly worthless; and (2) at the present time there is a glut of plutonium available from the dismantlement of nuclear weapons.]
Are we speculating here on new technology like "fusion" power? Hardly.
The first reactor ever to produce electric power from nuclear energy was a "liquid metal fast breeder reactor" known as the EBR-I. (By the way, liquid metal means that the coolant was not our old friend water, but liquid sodium; fast means that it used "fast neutrons," not the slowed-down, moderated variety.) Designed by physicist Walter Zinn in 1944, his brainchild went critical at 11 am, December 20, 1951 - producing the first steam in history produced by man-made nuclear heat. Like the Manhattan reactor in Chicago and the SLOWPOKE reactor in Canada, EBR-I was not designed to produce electrical power but to prove the concept of fuel breeding (which it did along with its successor, EBR-II). [Declared a national landmark in 1966, the EBR-I is open to the public from mid June to mid September. Located eighteen miles southeast of Arco, Idaho, on Highway 26, visitors must be at least sixteen years old (too much neutron violence?) and U.S. citizens (fear of spies who might steal this technology?).]
The EBR-II had "on the spot reprocessing," which reprocessed 35,000 fuel elements between 1965 and 1969. But the facility was not without problems: the fence around it kept out the coyotes, causing the rabbit population to outbreed the reactor.
Does the ERB-II sound a little familiar? It should since it has another name we used in chapter 21 - the Integral Fast Reactor (IFR).
While many U.S. politicians have never heard of breeder technology, Europeans have. Sadly, "Green" activists there have been successful in shutting them down or keeping them from ever starting up.
This happens in every one of the world's 500 power reactors, plus thousands of research reactors, every day they are in operation. In fact, a sizable fraction (up to about 30%) of electrical energy generated by a power plant comes from this plutonium, which arises as a natural consequence of the uranium fission reaction - without any effort on our part - and supplements the scarce U235 fuel.
Some reactors, however, are designed to intentionally make plutonium. If it is to be used in bombs, it is normally made in a reactor with another modulator - such as the carbon-modulated reactor at Chernobyl. A reactor designed specifically to make only fuel-grade plutonium is called a breeder reactor, since new fuel is "bred" from an almost worthless byproduct of the refining cycle. [Breeder technology seems to be on hold for a couple of reasons: (1) in the prevailing anti-nuclear climate, few entrepreneurs or speculators are willing to make investments in nuclear power for fear of laws that can make their investment instantly worthless; and (2) at the present time there is a glut of plutonium available from the dismantlement of nuclear weapons.]
Are we speculating here on new technology like "fusion" power? Hardly.
The first reactor ever to produce electric power from nuclear energy was a "liquid metal fast breeder reactor" known as the EBR-I. (By the way, liquid metal means that the coolant was not our old friend water, but liquid sodium; fast means that it used "fast neutrons," not the slowed-down, moderated variety.) Designed by physicist Walter Zinn in 1944, his brainchild went critical at 11 am, December 20, 1951 - producing the first steam in history produced by man-made nuclear heat. Like the Manhattan reactor in Chicago and the SLOWPOKE reactor in Canada, EBR-I was not designed to produce electrical power but to prove the concept of fuel breeding (which it did along with its successor, EBR-II). [Declared a national landmark in 1966, the EBR-I is open to the public from mid June to mid September. Located eighteen miles southeast of Arco, Idaho, on Highway 26, visitors must be at least sixteen years old (too much neutron violence?) and U.S. citizens (fear of spies who might steal this technology?).]
The EBR-II had "on the spot reprocessing," which reprocessed 35,000 fuel elements between 1965 and 1969. But the facility was not without problems: the fence around it kept out the coyotes, causing the rabbit population to outbreed the reactor.
Does the ERB-II sound a little familiar? It should since it has another name we used in chapter 21 - the Integral Fast Reactor (IFR).
While many U.S. politicians have never heard of breeder technology, Europeans have. Sadly, "Green" activists there have been successful in shutting them down or keeping them from ever starting up.
Wednesday, March 2, 2016
The Most Toxic Substance on Earth?
One of the noisiest guns in the anti-nuclear arsenal has been the cultivated fear of plutonium. "The most toxic substance known to man," so the mantra goes - in complete disregard to toxicity studies showing the element to be about as toxic as caffeine and 1/1,000,000,000,000 the toxicity of botulism toxin. Even in the health physics field, however, there has been a great deal of concern over inhaled plutonium, because it is an alpha emitter shooting nuclear cannon balls directly into adjacent lung tissue. If you presume radiation is a major cause of cancer, it is only logical to see chronic exposure from an alpha source within the lungs as extremely dangerous. But just as with radon exposure in mining environments, plutonium may not be nearly as dangerous as earlier believed.
During the urgent atomic bomb development period of 1944-45, some workers were exposed to plutonium fumes and extremely fine dust, which accumulated primarily in lung tissue. Twenty-six of these exposed males were followed with regular examinations every five years starting in 1952. When the initial study of these examinations began in 1973 [Hempelmann, L.H. et al. Manhattan Project plutonium workers. A twenty-seven year follow-up study of selected cases. Health Physics, 25, 461, 1973], one subject had already died of a heart attack. Anti-nuclear scientists, such as John Gofman, predicted shortened life spans from radiation-induced lung cancer. [Gofman, J.W., Radiation and Human Health, Sierra Clue Books, San Francisco, 1981.]
But apparently, someone forgot to tell the workers.
At the time of the 1986-87 examination period, with an average of age of sixty-six years, twenty-two of the twenty-five subjects had refused to die on Gofman's schedule. One had died in an automobile accident, another of a heart attack at age sixty-two, and the third - a pack-a-day-plus smoker - had succumbed to lung cancer in his seventy-second year. (It may be of some interest that this person, identified as Subject #10, was in the lower half of estimated plutonium deposits.)
Because only twenty-six individuals were involved, the study has no statistical significance - which is to say that chance could have been at work selecting certain men who were unusually tolerant to the effects of inhaled plutonium. But the data is also suggestive of a lesser response to plutonium than the LNT dose-response would predict.
Anti-nuclear activists are fond of saying that "a single gamma ray can lead to cancer." Eight of the atomic bomb workers - all living at the end of 1987 - had received a dose of more than 2,000,000,000,000,000 alpha particles, which is the equivalent of 8,000,000,000,000,000 gamma rays (assuming a Q of 4). Not only were the "victims" alive, but they were healthier than their peers who weren't lucky enough to inhale plutonium dust more than forty years earlier.
If this study were the only one indicating a biopositive dose-response from plutonium ingestion, it might be written off as an anomaly. But, quoting from a paper by Voelz and Lawrence [Voelz, G.L. and Lawrence, J.N.P. A forty-two-year medical follow-up of Manhattan Project plutonium workers. Health Physics, Vol. 61, 1991. For more information, you might also refer to Voelz, G.L. et al. Mortality study of Los Alamos workers with higher exposures to plutonium. Epidemiology applied to health physics. Proceedings of the Health Physics Society, Albuquerque, N.M. Report CONF-83010, 318, 1983]:
"Other studies of Pu-exposed workers have not demonstrated excesses of lung cancer. In 224 white male Pu-exposed workers, selected on the basis of each having a 1974 estimated Pu deposition in excess of 370Bq (10 nCi), only one death from lung cancer occurred over at 33-year follow-up period. The SMR for lung cancer based on U.S. rates was 0.2 (95% C.I.=0,1.1)."
Lest you have forgotten the definition, an SMR of 0.2 means that the lung cancer rate for the workers exposed to plutonium was one-fifth that of the general population.
Don't take this as an indication that plutonium is never dangerous when ingested. All the heavy metals are toxic to some degree, and though a relatively benign alpha emitter, it has the potential for being dangerous in large amounts. Several studies noted by Voelz in which beagles were exposed to very high doses produced extremely severe consequences. But hormesis is about the differences in effects of a toxin depending on the dose and/or dose rate. Evidence in these studies clearly suggests that plutonium may be an effective hormetin.
During the urgent atomic bomb development period of 1944-45, some workers were exposed to plutonium fumes and extremely fine dust, which accumulated primarily in lung tissue. Twenty-six of these exposed males were followed with regular examinations every five years starting in 1952. When the initial study of these examinations began in 1973 [Hempelmann, L.H. et al. Manhattan Project plutonium workers. A twenty-seven year follow-up study of selected cases. Health Physics, 25, 461, 1973], one subject had already died of a heart attack. Anti-nuclear scientists, such as John Gofman, predicted shortened life spans from radiation-induced lung cancer. [Gofman, J.W., Radiation and Human Health, Sierra Clue Books, San Francisco, 1981.]
But apparently, someone forgot to tell the workers.
At the time of the 1986-87 examination period, with an average of age of sixty-six years, twenty-two of the twenty-five subjects had refused to die on Gofman's schedule. One had died in an automobile accident, another of a heart attack at age sixty-two, and the third - a pack-a-day-plus smoker - had succumbed to lung cancer in his seventy-second year. (It may be of some interest that this person, identified as Subject #10, was in the lower half of estimated plutonium deposits.)
Because only twenty-six individuals were involved, the study has no statistical significance - which is to say that chance could have been at work selecting certain men who were unusually tolerant to the effects of inhaled plutonium. But the data is also suggestive of a lesser response to plutonium than the LNT dose-response would predict.
Anti-nuclear activists are fond of saying that "a single gamma ray can lead to cancer." Eight of the atomic bomb workers - all living at the end of 1987 - had received a dose of more than 2,000,000,000,000,000 alpha particles, which is the equivalent of 8,000,000,000,000,000 gamma rays (assuming a Q of 4). Not only were the "victims" alive, but they were healthier than their peers who weren't lucky enough to inhale plutonium dust more than forty years earlier.
If this study were the only one indicating a biopositive dose-response from plutonium ingestion, it might be written off as an anomaly. But, quoting from a paper by Voelz and Lawrence [Voelz, G.L. and Lawrence, J.N.P. A forty-two-year medical follow-up of Manhattan Project plutonium workers. Health Physics, Vol. 61, 1991. For more information, you might also refer to Voelz, G.L. et al. Mortality study of Los Alamos workers with higher exposures to plutonium. Epidemiology applied to health physics. Proceedings of the Health Physics Society, Albuquerque, N.M. Report CONF-83010, 318, 1983]:
"Other studies of Pu-exposed workers have not demonstrated excesses of lung cancer. In 224 white male Pu-exposed workers, selected on the basis of each having a 1974 estimated Pu deposition in excess of 370Bq (10 nCi), only one death from lung cancer occurred over at 33-year follow-up period. The SMR for lung cancer based on U.S. rates was 0.2 (95% C.I.=0,1.1)."
Lest you have forgotten the definition, an SMR of 0.2 means that the lung cancer rate for the workers exposed to plutonium was one-fifth that of the general population.
Don't take this as an indication that plutonium is never dangerous when ingested. All the heavy metals are toxic to some degree, and though a relatively benign alpha emitter, it has the potential for being dangerous in large amounts. Several studies noted by Voelz in which beagles were exposed to very high doses produced extremely severe consequences. But hormesis is about the differences in effects of a toxin depending on the dose and/or dose rate. Evidence in these studies clearly suggests that plutonium may be an effective hormetin.
Sunday, January 31, 2016
A Very Short History of Radiation Hormesis
The extremely tall people on Niue Island (averaging height 6'6") receive 10 times more radiation from the soil than the world average. [Eugaster, Subradiation experiments concerning the concept of the natural radiation background, Aerospace Medicine, 35, 524, 1964.]
Why, you might logically ask, was the hormesis phenomenon not discovered until some eighty years after Roentgen, Becquerel, and the Curies made their contributions to radiation science? Why was there not an earlier Professor Luckey? [Professor Luckey is credited with coining the term "Radiation Hormesis" from his 1981 book Hormesis with Ionizing Radiation.]
Actually there was of sorts, and he, oddly enough, was also a professor at the University of Missouri. In 1896, Professor W. Shrader inoculated guinea pigs with the diphtheria bacillus. [Shrader, W. Experiments with X-rays upon germs. Electrical Engineering, 22, 170, 1896.]
The group exposed to X-rays prior to inoculation survived; the unexposed cohort died within twenty-four hours. Shrader, in the same series of experiments, was apparently the first person to discover that "Roentgen Rays" could be used to kill germs.
During the early twentieth century, radiation was used for a variety of experimental therapies, but the doses were generally far above hormetic levels and may well have caused more harm than good. Patent medicines such as "Radithor" (more on this in chapter 24) were popular, with single doses having nearly a million times the daily radium intake allowed by current government regulators. Hundreds of thousands of vials of elixirs were consumed without any widespread harm occurring and with a sizable number of "miracle cures" being reported. Few controls, however, were employed to scientifically assess the actual worth of the treatments leaving one to believe that most of these "cures" may have been either the product of advertising hype or a placebo effect.
Medical research wasn't the big draw for world-class physicists. We might remember that in the early days of radiation experimentation important discoveries were being made almost daily, while health considerations - except, possibly, for the annoying, minor and superficial skin "beta burns" - were considered to be of no consequence. The doses of radiation these unprotected experimenters received are estimated to exceed by thousands of times the maximums under which today's nuclear industry workers are allowed to continue on the job.
Madame Curie, discoverer of both polonium and radium, offers a good example of the "non-standards" of the day. [In 1516, a silver lode was discovered in St. Joachim's Dale (Joachimsthal), which was - naturally - confiscated by the government of Count von Schlick. Coins minted from this mine were known as Joachimsthalers, which (for obvious reasons) came to be known as thalers - in English, dollars. It was from this mine that the Curies obtained pitchblende - an ore rich in uranium and its daughters, radium and polonium.]
It is anecdotal that whenever Marie Sklodowska [in case you were curious why she named her first discovery for Poland] Curie walked into a room, electroscopes immediately discharged. [Gold is so malleable that it can be pressed into leaves less than 1/10,000 of an inch thick. If you hang two pieces of leaf in an air-filled jar, with provision to charge both - you have an electroscope. Charging the leaves with the same polarity causes them to "push apart" and, because they are so light, the electrostatic "pushing" force exceeds the gravitational force that would cause them to "droop" into a vertical position. Such devices were used to assay the content of uranium ores - not from the non-penetrating alpha radiation of the uranium, but from the accumulated daughters of which the gamma ray emitting radium was a significant component. Air, when ionized, is a conductor that discharged the electroscope at a rate proportional to the amount of ionizing radiation present.]
It is almost certain that she had an enormous lung burden of radium - the element she was extracting from uranium ore - which took quite a bit of patience, since there are only about 0.003 grams of radium per ton of ore. Madam Curie died almost certainly from the effects of long-term and extremely high doses of radiation. Yet, at age sixty-six, she still exceeded by ten years the life expectancy of her day.
Later in the century, the subject of hormesis would have doubtlessly been trifling compared to other matters. From August 1939 - when a letter from Albert Einstein was delivered to Franklin Roosevelt recommending the development of an atomic bomb - until the end of World War II, the focus of virtually the entire nulcear physics community became the Manhattan project. (This venture, equivalent in size to the total automotive industry at that time, is described in fascinating detail in The Making of the Atomic Bomb [Richard Rhodes, Simon & Schuster, New York, 1986].)
Certainly the scientists were aware of potential dangers from radiation - especially the highly penetrating neutrons from "atomic piles" - but these risks were minimal, compared with the reality of thousands of deaths from the war every day. Concerns about low-level radiation - either harmful or beneficial - weren't even on the radar scope.
Interestingly, the only health physics experiment I've ever come across that occurred during the Manhattan project was indicative of radiation hormesis:
"In 1943, a group of [radiation scientists] on the Manhattan District Project were worried about the unknown toxicity of uranium. They grew a colony of rats in an atmosphere laden with sufficient uranium dust to kill them fast (the Manhattan Project didn't have time for fancy radiobiologists). As a control, a similar colony breathed clean air. After several months, nothing happened, but eventually the rats lived out their natural lifespans, with one surprise: the first health physics experiment demonstrated that rats who breathed uranium dust lived longer and were happier (i.e., had a better reproductive history) than normal rats. Not a tumor in the bunch." [From a letter by Marshall Brucer, M.D. to Time magazine (from the files of Petr Beckmann).]
During this period there are reports of relatively minor medical experimentation to determine the effect of ionizing radiation on the healing of wounds. The exposure levels, however, were high (1 Gy or 100 rem) - suggesting its use as a bactericide. The availability of antibiotics in 1942, and the post-Hiroshima bombing concerns over high-level dangers, caused a loss of interest in research of this nature by the end of World War II.
After the war, the Japanese cities of Hiroshima and Nagasaki became laboratories for research on the effects of radiation on humans. But the focal point was on the high-dose subjects - in particular on their excess cancers and the possible mutational effects on children. When low-dose victims showed beneficial health effects, the data were ignored as being anomalies (a fancy scientific words for "it doesn't fit in with what we're expecting").
Luckey addresses this subject:
"Statistical analysis of observed data was missing in many reports of experiments involving low doses of ionizing radiation. Most of the reports simply indicated that an unexpected phenomenon had been observed, but the researchers failed to pursue it systematically... Any unexpected result was rejected by the 95% rule: One experiment in each twenty was accepted as a variant. Closer inspection showed this was a consistent result; it usually occurred in the group exposed to the least radiation, the only one in the hormetic range. Hormetic data were ignored because they did not fit the models of the zero thesis." [Radiation Hormesis, p. 45.]
When someone really writes a history of radiation hormesis, the first "official" recognition of the phenomenon will go to the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in a 1994 report "Adaptive Responses to Radiation in Cells and Organisms":
"Manifestations of the adaptation described in mammals after exposure to low doses of radiation include accelerated growth rate in the young, increase in reproductive ability, extended life-span, stimulatory effects on the immune system, and a lower than expected incidence of spontaneous tumors."
You might want to read that again.
Why, you might logically ask, was the hormesis phenomenon not discovered until some eighty years after Roentgen, Becquerel, and the Curies made their contributions to radiation science? Why was there not an earlier Professor Luckey? [Professor Luckey is credited with coining the term "Radiation Hormesis" from his 1981 book Hormesis with Ionizing Radiation.]
Actually there was of sorts, and he, oddly enough, was also a professor at the University of Missouri. In 1896, Professor W. Shrader inoculated guinea pigs with the diphtheria bacillus. [Shrader, W. Experiments with X-rays upon germs. Electrical Engineering, 22, 170, 1896.]
The group exposed to X-rays prior to inoculation survived; the unexposed cohort died within twenty-four hours. Shrader, in the same series of experiments, was apparently the first person to discover that "Roentgen Rays" could be used to kill germs.
During the early twentieth century, radiation was used for a variety of experimental therapies, but the doses were generally far above hormetic levels and may well have caused more harm than good. Patent medicines such as "Radithor" (more on this in chapter 24) were popular, with single doses having nearly a million times the daily radium intake allowed by current government regulators. Hundreds of thousands of vials of elixirs were consumed without any widespread harm occurring and with a sizable number of "miracle cures" being reported. Few controls, however, were employed to scientifically assess the actual worth of the treatments leaving one to believe that most of these "cures" may have been either the product of advertising hype or a placebo effect.
Medical research wasn't the big draw for world-class physicists. We might remember that in the early days of radiation experimentation important discoveries were being made almost daily, while health considerations - except, possibly, for the annoying, minor and superficial skin "beta burns" - were considered to be of no consequence. The doses of radiation these unprotected experimenters received are estimated to exceed by thousands of times the maximums under which today's nuclear industry workers are allowed to continue on the job.
Madame Curie, discoverer of both polonium and radium, offers a good example of the "non-standards" of the day. [In 1516, a silver lode was discovered in St. Joachim's Dale (Joachimsthal), which was - naturally - confiscated by the government of Count von Schlick. Coins minted from this mine were known as Joachimsthalers, which (for obvious reasons) came to be known as thalers - in English, dollars. It was from this mine that the Curies obtained pitchblende - an ore rich in uranium and its daughters, radium and polonium.]
It is anecdotal that whenever Marie Sklodowska [in case you were curious why she named her first discovery for Poland] Curie walked into a room, electroscopes immediately discharged. [Gold is so malleable that it can be pressed into leaves less than 1/10,000 of an inch thick. If you hang two pieces of leaf in an air-filled jar, with provision to charge both - you have an electroscope. Charging the leaves with the same polarity causes them to "push apart" and, because they are so light, the electrostatic "pushing" force exceeds the gravitational force that would cause them to "droop" into a vertical position. Such devices were used to assay the content of uranium ores - not from the non-penetrating alpha radiation of the uranium, but from the accumulated daughters of which the gamma ray emitting radium was a significant component. Air, when ionized, is a conductor that discharged the electroscope at a rate proportional to the amount of ionizing radiation present.]
It is almost certain that she had an enormous lung burden of radium - the element she was extracting from uranium ore - which took quite a bit of patience, since there are only about 0.003 grams of radium per ton of ore. Madam Curie died almost certainly from the effects of long-term and extremely high doses of radiation. Yet, at age sixty-six, she still exceeded by ten years the life expectancy of her day.
Later in the century, the subject of hormesis would have doubtlessly been trifling compared to other matters. From August 1939 - when a letter from Albert Einstein was delivered to Franklin Roosevelt recommending the development of an atomic bomb - until the end of World War II, the focus of virtually the entire nulcear physics community became the Manhattan project. (This venture, equivalent in size to the total automotive industry at that time, is described in fascinating detail in The Making of the Atomic Bomb [Richard Rhodes, Simon & Schuster, New York, 1986].)
Certainly the scientists were aware of potential dangers from radiation - especially the highly penetrating neutrons from "atomic piles" - but these risks were minimal, compared with the reality of thousands of deaths from the war every day. Concerns about low-level radiation - either harmful or beneficial - weren't even on the radar scope.
Interestingly, the only health physics experiment I've ever come across that occurred during the Manhattan project was indicative of radiation hormesis:
"In 1943, a group of [radiation scientists] on the Manhattan District Project were worried about the unknown toxicity of uranium. They grew a colony of rats in an atmosphere laden with sufficient uranium dust to kill them fast (the Manhattan Project didn't have time for fancy radiobiologists). As a control, a similar colony breathed clean air. After several months, nothing happened, but eventually the rats lived out their natural lifespans, with one surprise: the first health physics experiment demonstrated that rats who breathed uranium dust lived longer and were happier (i.e., had a better reproductive history) than normal rats. Not a tumor in the bunch." [From a letter by Marshall Brucer, M.D. to Time magazine (from the files of Petr Beckmann).]
During this period there are reports of relatively minor medical experimentation to determine the effect of ionizing radiation on the healing of wounds. The exposure levels, however, were high (1 Gy or 100 rem) - suggesting its use as a bactericide. The availability of antibiotics in 1942, and the post-Hiroshima bombing concerns over high-level dangers, caused a loss of interest in research of this nature by the end of World War II.
After the war, the Japanese cities of Hiroshima and Nagasaki became laboratories for research on the effects of radiation on humans. But the focal point was on the high-dose subjects - in particular on their excess cancers and the possible mutational effects on children. When low-dose victims showed beneficial health effects, the data were ignored as being anomalies (a fancy scientific words for "it doesn't fit in with what we're expecting").
Luckey addresses this subject:
"Statistical analysis of observed data was missing in many reports of experiments involving low doses of ionizing radiation. Most of the reports simply indicated that an unexpected phenomenon had been observed, but the researchers failed to pursue it systematically... Any unexpected result was rejected by the 95% rule: One experiment in each twenty was accepted as a variant. Closer inspection showed this was a consistent result; it usually occurred in the group exposed to the least radiation, the only one in the hormetic range. Hormetic data were ignored because they did not fit the models of the zero thesis." [Radiation Hormesis, p. 45.]
When someone really writes a history of radiation hormesis, the first "official" recognition of the phenomenon will go to the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in a 1994 report "Adaptive Responses to Radiation in Cells and Organisms":
"Manifestations of the adaptation described in mammals after exposure to low doses of radiation include accelerated growth rate in the young, increase in reproductive ability, extended life-span, stimulatory effects on the immune system, and a lower than expected incidence of spontaneous tumors."
You might want to read that again.
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