Wednesday, April 13, 2016
Five-Page Penalty for Delay of Book
Sorry to have spent so long on the subject of terrorism. It is far afield from hormesis and the positive applications of nuclear energy, but it is a false argument so often used by anti-nuclear people, and it is never refuted - or even questioned - in the media. We might note that our overseas neighbors know this "threat of terrorism" malarkey is total rot - but what do they care what we think? If it goes on long enough, they will be able to sell high-energy content products to us... while we lap up good old safe solar energy in our cotton fields. Suffice it to say that the "terrorists with the plutonium" excuse for stopping a major reprocessing facility is as thin as a dime - and worth far less.
Tuesday, April 12, 2016
There Has Just Got To Be A Better Way
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.
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.
Monday, April 11, 2016
Where the Terrorists Have Already Won
In 1978, Jimmy Carter reneged on the opening of a reprocessing plant that was nearing completion in Barnwell, South Carolina. This facility was to take "spent" fuel rods from power reactors owned by the utilities, dissolve them in acid, then separate the uranium and plutonium from the contaminants that would "poison" and eventually stop the chain reaction. The highly radioactive progeny of the energy-producing reactions - amounting to some 1% or 2% of the volume - would be disposed of by any one of a number of perfectly safe methods. The fuel portion would then be reformed into uranium or "MOX" pellets for insertion into fuel assemblies.
Hold on. Could one infer from this that these "spent" fuel elements contain in excess of 90% of their intial fuel? Yes, one could. Is this what we plan to bury under Yucca Mountain? Precisely.
Does this make sense to you? It certainly doesn't to the English, French, Japanese, Russians, and others who think we are absolutely nuts for planning to bury unbelievable amounts of readily obtainable energy. But it made sense to the Carter administration, and even though Reagan reversed the decision, there were no corporate takers who were willing to risk their shareholders' money on a project that could be changed by the whim of a government with a history of caving in to the slightest pseudo-environmentalist pressure. And there would certainly be pressure - since, as we "know," all radiation is dangerous, since any gamma ray could cause cancer... even though the odds against it are 30 quadrillion to one.
What was the reason - excuse, really - that the Carter administration used to stop reprocessing? It was the threat of terrorism. Let's consider briefly the problems from the standpoint of terrorists who are planning a heist of plutonium, with which they intend to make a bomb.
Hold on. Could one infer from this that these "spent" fuel elements contain in excess of 90% of their intial fuel? Yes, one could. Is this what we plan to bury under Yucca Mountain? Precisely.
Does this make sense to you? It certainly doesn't to the English, French, Japanese, Russians, and others who think we are absolutely nuts for planning to bury unbelievable amounts of readily obtainable energy. But it made sense to the Carter administration, and even though Reagan reversed the decision, there were no corporate takers who were willing to risk their shareholders' money on a project that could be changed by the whim of a government with a history of caving in to the slightest pseudo-environmentalist pressure. And there would certainly be pressure - since, as we "know," all radiation is dangerous, since any gamma ray could cause cancer... even though the odds against it are 30 quadrillion to one.
What was the reason - excuse, really - that the Carter administration used to stop reprocessing? It was the threat of terrorism. Let's consider briefly the problems from the standpoint of terrorists who are planning a heist of plutonium, with which they intend to make a bomb.
Sunday, April 10, 2016
Dirty Bombs
We have been led to believe - on the basis of the LNT theory and collective dose - that terrorists could mount an effective attack by the use of "dirty bombs," i.e., bombs that spread radioactive materials by use of conventional explosives. At present, such bombs would be an effective weapon, since the fear of radiation, as in Goia and Three Mile Island, would doubtlessly cause panic and result in deaths from heart attacks, auto accidents and the like. But if we understand the actual effects of radiation, we can respect it without allowing it to overcome our rational thought. Let's look at the worst case.
Terrorists park a car bomb filled with strontium 90, which has a long half-life (twenty-nine years) and the propensity for replacing calcium in bones. At noon, with the maximum numbers of people walking down Wall Street on the way to lunch, the bomb is exploded, and strontium 90 is blasted into the air. Radioactive debris is scattered by the wind over an area of many blocks.
Let's look at this scenario as graduates of Hormesis U. First, where are the terrorists going to get a carload of strontium 90? It is a product of nuclear explosions and found in reactor "wastes." Like so many other "waste" radionuclides, it is a valuable commodity being used in medical and agricultural tracers as well as in RTGs (radio thermo-electric generators) for navigational beacons and weather stations. Medically, it is used for treatment of eye diseases and bone cancer. It is a valuable commodity and certainly not widely available in quantities like the ammonium nitrate and fuel oil used in the Oklahoma City bombing.
The EPA's Radiation Information website [www.epa.gov/radiation/radionuclides/strontium.htm] tells us that "swallowing Sr-90 with food or water is the primary pathway of intake."
The same source tells us that strontium 90 is a beta emitter. Graduates of Hormesis U. know that beta radiation can travel only a few feet through air and causes minor burns (beta burns) to exposed skin. Knowing this, what action would be required after a terrorist went to the trouble and expense to disburse this most dreaded of radioactive materials in the canyons of Manhattan? I would suggest a warning to the local inhabitants not to lick the pavement or buildings. After that, I would wait for a rain that would wash the dust down the sewers leading to the Atlantic Ocean, where there are already quadrillions of curies (septillions of becquerels) that will still be there long after the vestiges of strontium 90 have disappeared. A potential problem: the sewer rats might be affected bio-positively and take charge of the large metropolitan cities.
So much for dirty bombs.
Terrorists park a car bomb filled with strontium 90, which has a long half-life (twenty-nine years) and the propensity for replacing calcium in bones. At noon, with the maximum numbers of people walking down Wall Street on the way to lunch, the bomb is exploded, and strontium 90 is blasted into the air. Radioactive debris is scattered by the wind over an area of many blocks.
Let's look at this scenario as graduates of Hormesis U. First, where are the terrorists going to get a carload of strontium 90? It is a product of nuclear explosions and found in reactor "wastes." Like so many other "waste" radionuclides, it is a valuable commodity being used in medical and agricultural tracers as well as in RTGs (radio thermo-electric generators) for navigational beacons and weather stations. Medically, it is used for treatment of eye diseases and bone cancer. It is a valuable commodity and certainly not widely available in quantities like the ammonium nitrate and fuel oil used in the Oklahoma City bombing.
The EPA's Radiation Information website [www.epa.gov/radiation/radionuclides/strontium.htm] tells us that "swallowing Sr-90 with food or water is the primary pathway of intake."
The same source tells us that strontium 90 is a beta emitter. Graduates of Hormesis U. know that beta radiation can travel only a few feet through air and causes minor burns (beta burns) to exposed skin. Knowing this, what action would be required after a terrorist went to the trouble and expense to disburse this most dreaded of radioactive materials in the canyons of Manhattan? I would suggest a warning to the local inhabitants not to lick the pavement or buildings. After that, I would wait for a rain that would wash the dust down the sewers leading to the Atlantic Ocean, where there are already quadrillions of curies (septillions of becquerels) that will still be there long after the vestiges of strontium 90 have disappeared. A potential problem: the sewer rats might be affected bio-positively and take charge of the large metropolitan cities.
So much for dirty bombs.
Saturday, April 9, 2016
The Dirty Bomb's Dirty Little Secret
Anyone who has the slightest familiarity with nuclear power knows that it is impossible to steal fuel from an operating reactor.
Is there a nuclear threat to Western civilization? No question. As long as there are nuclear weapons and Islamic terrorists who would murder thousands of innocents without conscience, such a possibility exists. Actions to prevent this are a subject far afield from hormesis, but one possibility might be to offer a higher-than-market price for plutonium to be blended into MOX, rendering it unusable for weapons, as a fuel for power reactors.
MOX is mixed oxide fuel composed of 7% plutonium mixed with depleted uranium. Currently about 2% of reactor fuel is MOX. A very good discussion of MOX and the use of reactor-grade plutonium in weapons can be found online at the following address: www.nic.com.au/nip42.htm.
Is there a nuclear threat to Western civilization? No question. As long as there are nuclear weapons and Islamic terrorists who would murder thousands of innocents without conscience, such a possibility exists. Actions to prevent this are a subject far afield from hormesis, but one possibility might be to offer a higher-than-market price for plutonium to be blended into MOX, rendering it unusable for weapons, as a fuel for power reactors.
MOX is mixed oxide fuel composed of 7% plutonium mixed with depleted uranium. Currently about 2% of reactor fuel is MOX. A very good discussion of MOX and the use of reactor-grade plutonium in weapons can be found online at the following address: www.nic.com.au/nip42.htm.
Friday, April 8, 2016
And Finally...
Many of us think in terms of our present energy situation and don't consider what benefits our world would have if the LNT did not cloud the minds of those who could do great works - if allowed to do so by the regulators. While the American Nuclear Society is still on the fence in regard to scrapping the LNT and recognizing the possibilities of hormesis, Gregg M. Taylor, the editor-in-chief of the organization's magazine - Nuclear News - wrote an absorbing editorial entitled, "We have met the solution, and it is us."
In this monograph, he noted that one of California's big problems - echoed in many countries around the world - is the availability of water for agricultural irrigation. Water from the Colorado River is coveted by all and is a constant source of political turmoil. But what if we built nuclear desalination plants, he asks, strategically located along the coast? They could be pollution free - with guppy rights properly observed.
One might wonder how this could dovetail into Dr. Cohen's extraction of uranium from the sea - surely there is a synergistic connection here as part of the desalination process could well be the initial step in obtaining the metal. How much more habitable - for people like you and me - would the Earth become if our deserts could be irrigated... at no cost except the premature use of the nuclear energy in uranium and thorium. They are going to lose their energy over time anyway - we're just appropriating it for our short-term use. Besides, a quarter of the uranium and two-thirds of the thorium would still have its energy when the sun flakes out on us in eight or ten billion years.
Editor Taylor also touches on another touchy subject: toxic wastes. Noting that most of us remember "disintegrators" from our sci-fi days, he observes that it takes only sufficient energy - which can be provided readily by clean nuclear sources - to reduce the most horrible kinds of toxic waste into its constituent atoms, which would totally lose their identity and could be recombined as the purest substances possible.
Let your mind roam free for a moment. What scourge of mankind might not be alleviated by sufficient energy availability?
***
If man is to advance to another higher plateau - past the industrial and information revolutions - it can be done only in conjunction with an unencumbered access to energy. Otherwise, we are dooming generations to untold misery and suffering.
In this monograph, he noted that one of California's big problems - echoed in many countries around the world - is the availability of water for agricultural irrigation. Water from the Colorado River is coveted by all and is a constant source of political turmoil. But what if we built nuclear desalination plants, he asks, strategically located along the coast? They could be pollution free - with guppy rights properly observed.
One might wonder how this could dovetail into Dr. Cohen's extraction of uranium from the sea - surely there is a synergistic connection here as part of the desalination process could well be the initial step in obtaining the metal. How much more habitable - for people like you and me - would the Earth become if our deserts could be irrigated... at no cost except the premature use of the nuclear energy in uranium and thorium. They are going to lose their energy over time anyway - we're just appropriating it for our short-term use. Besides, a quarter of the uranium and two-thirds of the thorium would still have its energy when the sun flakes out on us in eight or ten billion years.
Editor Taylor also touches on another touchy subject: toxic wastes. Noting that most of us remember "disintegrators" from our sci-fi days, he observes that it takes only sufficient energy - which can be provided readily by clean nuclear sources - to reduce the most horrible kinds of toxic waste into its constituent atoms, which would totally lose their identity and could be recombined as the purest substances possible.
Let your mind roam free for a moment. What scourge of mankind might not be alleviated by sufficient energy availability?
- Floods and hurricanes? Better materials requiring more energy, high dikes - both a function of available energy.
- Starvation? Hydroponics from desalinated water.
- Locusts? Airplanes, chemicals, huge nuclear flyswatters (just kidding).
***
If man is to advance to another higher plateau - past the industrial and information revolutions - it can be done only in conjunction with an unencumbered access to energy. Otherwise, we are dooming generations to untold misery and suffering.
Thursday, April 7, 2016
What's the Holdup?
Fuel reprocessing and breeder reactors are major world-class technologies that our government is keeping its citizens and non-international businesses from participating in. Without it, the fuel for our existing reactors is in jeopardy of becoming uneconomical to mine and process within the next several decades. And without it, we as a nation will be starved for energy and un-competitive in the world marketplace. How can this be? Who would stifle the production and distribution of energy? Who would not stem the misery brought about by an energy poverty?
I am sad to say, there are those who seek this condition. I don't think they believe themselves hateful or misanthropic. They feel that sacrificing others today will bring about a better life for many more others. They are the spiritual descendants of Thomas Malthus and Ned Ludd - and are not aware of the vast gains of the industrial revolution in general, and nuclear power in particular. Nor are they aware of the ability of markets to provide a life with great worth for billions of participants and critics like.
I feel sorry for them in their lack of knowledge.
I am sad to say, there are those who seek this condition. I don't think they believe themselves hateful or misanthropic. They feel that sacrificing others today will bring about a better life for many more others. They are the spiritual descendants of Thomas Malthus and Ned Ludd - and are not aware of the vast gains of the industrial revolution in general, and nuclear power in particular. Nor are they aware of the ability of markets to provide a life with great worth for billions of participants and critics like.
I feel sorry for them in their lack of knowledge.
Wednesday, April 6, 2016
Energy Sources for the Future - Take Your (Limited) Choices
Fossil fuels will be around as long as mankind, but there is historical reason to believe that they - like whale oil and placer gold - will be diminishing in economically recoverable supplies. "Renewable sources" - such as solar, wind, hydro, tidal, geothermal and chicken manure energies - are frankly just not going to fill the bill when it comes to an industrial economy with billions of people requiring an ever-increasing supply of energy. [For instance, energy-balance calculations reveal that the energy cost of building a solar plant exceeds the energy it is expected to capture and utilize over a forty-year lifetime.]
Fusion, as noted, would be wonderful... if it is possible as a source, and if we have the ability to develop it in the next twenty generations. Which leaves us with one proven source of sufficient energy for the world during the next several millennia: nuclear fission. There are, as far as is known today - and we know quite a bit - only three choices for fissionable materials:
Number 1: Uranium 235. This is the granddad of fission. It naturally occurs as 0.7% of the element found on Earth, and - if economically recoverable supplies are considered - is probably good for powering the world's energy needs for the next century or so. Many observers say forty years, but "Julian Simon's Law" would no doubt govern this commodity also. [Simon, Julian. The Ultimate Resource, Princeton University Press, Princeton, 1996.]
Number 2: Plutonium 239. Easily "bred" from common uranium 238, transmutation of existing stockpiles should last several hundred years at present use rates. But as Dr. Cohen points out in The Nuclear Energy Option, with breeder technology it becomes economical to separate uranium from sea water - where there are some 2 trillion curies - allowing man all the energy he needs until the sun burns out in 4 or 5 billion years.
Number 3: Uranium 233. This is the sleeper. When thorium 232 is exposed to neutrons, as in the transmutation of U238 to Pu239, another miraculous thing happens. Dirt becomes and incredible energy source. As mentioned in chapter 1, the Earth's surface averages 2.5 tons of thorium in the first foot of each square mile of area. The late Dr. Edward Teller was a strong advocate of thorium transmutation using a CANDU-type heavy-water reactor. His design would allow plentiful and inexpensive thorium to be entered in one side of the reactor, converted slowly to U232, which would be fissioned for power, with the "really spent" fuel exiting from the other side months or years later. He calculates this would give earthlings sufficient energy to provide for the next seven ice ages. [Teller is known as the "Father of the H-bomb" - but more accurately described as the defender of the free world from Soviet totalitarianism. See "CANDU Is Really Remarkable," Power Projections, May 1980.]
Add this to Dr. Cohen's four or five billion years, and we're really starting to talk about some time.
Fusion, as noted, would be wonderful... if it is possible as a source, and if we have the ability to develop it in the next twenty generations. Which leaves us with one proven source of sufficient energy for the world during the next several millennia: nuclear fission. There are, as far as is known today - and we know quite a bit - only three choices for fissionable materials:
Number 1: Uranium 235. This is the granddad of fission. It naturally occurs as 0.7% of the element found on Earth, and - if economically recoverable supplies are considered - is probably good for powering the world's energy needs for the next century or so. Many observers say forty years, but "Julian Simon's Law" would no doubt govern this commodity also. [Simon, Julian. The Ultimate Resource, Princeton University Press, Princeton, 1996.]
Number 2: Plutonium 239. Easily "bred" from common uranium 238, transmutation of existing stockpiles should last several hundred years at present use rates. But as Dr. Cohen points out in The Nuclear Energy Option, with breeder technology it becomes economical to separate uranium from sea water - where there are some 2 trillion curies - allowing man all the energy he needs until the sun burns out in 4 or 5 billion years.
Number 3: Uranium 233. This is the sleeper. When thorium 232 is exposed to neutrons, as in the transmutation of U238 to Pu239, another miraculous thing happens. Dirt becomes and incredible energy source. As mentioned in chapter 1, the Earth's surface averages 2.5 tons of thorium in the first foot of each square mile of area. The late Dr. Edward Teller was a strong advocate of thorium transmutation using a CANDU-type heavy-water reactor. His design would allow plentiful and inexpensive thorium to be entered in one side of the reactor, converted slowly to U232, which would be fissioned for power, with the "really spent" fuel exiting from the other side months or years later. He calculates this would give earthlings sufficient energy to provide for the next seven ice ages. [Teller is known as the "Father of the H-bomb" - but more accurately described as the defender of the free world from Soviet totalitarianism. See "CANDU Is Really Remarkable," Power Projections, May 1980.]
Add this to Dr. Cohen's four or five billion years, and we're really starting to talk about some time.
Tuesday, April 5, 2016
But What About Fusion?
It is so inviting... to think that our planet can be powered from ocean water. That, as you probably well know, is the expectation of many who would eschew other forms of energy generation. "Cold fusion" - which many of us would hope to be a viable energy source - is unproven. Which leads, naturally, to the hot variety. And I do mean hot!
You may remember from your freshman days at Hormesis U., that both deuterium and tritium are isotopes of hydrogen. (See chapter 5 if your memory is a bit rusty.) As it is generally understood, a fusion reaction in the sun occurs at temperatures in excess of 1,000,000 degrees Fahrenheit, when a deuterium and a tritium atom are crushed together to form helium and expel a neutron. It would be much cleaner if two deuterium atoms could do the trick without a neutron chaperone, but the universe just wasn't made that way. And while it's true that there is a virtually infinite supply of deuterium in ocean water, the horrible fact is: there isn't any tritium. (OK, a few quadrillion atoms or so, but not any that we can extract.) In fact, in the entire United States, there isn't much tritium at all, since your government considers this beta emitter - used on luminous watch dials - to be hazardous to your life. (Please be appreciative.)
Where would we get the tritium? I don't know, and I don't think anyone else does either. But there are other problems that I suspect are overwhelming in light of our present-day engineering and material capabilities - and may be physically impossible to solve. [For more on this subject, see the August 1999 edition of The Energy Advocate, published by Howard Hayden, professor emeritus of Physics, University of Connecticut. P.O. Box 7595, Pueblo West, CO 81007 - or www.EnergyAdvocate.com. ($35/year.)]
First, the energy required to magnetically contain the process (the only way it can be contained, since these temperatures decompose all materials into constituent atoms) invariably requires more energy than can be generated. Yet if, and when, this obstacle can be overcome, we have the problem of that pesky neutron.
While other particles can be redirected magnetically to where they have little danger to humans or equipment, the electrically neutral neutron has a mind of its own. When a plethora of neutrons are released around normal materials, those materials are transmuted into other element that are typically radioactive. Wouldn't this make the fusion reactor radioactive? Yes it would, which is probably why hot-fusion experiments reportedly must be cooled-down, dismantled, and decontaminated after every test run of only a few seconds. This might prompt us to ask, "What about the delivery of energy, twenty-four hours per day, 365 days per year?" There are, in my opinion, two choices.
You may remember from your freshman days at Hormesis U., that both deuterium and tritium are isotopes of hydrogen. (See chapter 5 if your memory is a bit rusty.) As it is generally understood, a fusion reaction in the sun occurs at temperatures in excess of 1,000,000 degrees Fahrenheit, when a deuterium and a tritium atom are crushed together to form helium and expel a neutron. It would be much cleaner if two deuterium atoms could do the trick without a neutron chaperone, but the universe just wasn't made that way. And while it's true that there is a virtually infinite supply of deuterium in ocean water, the horrible fact is: there isn't any tritium. (OK, a few quadrillion atoms or so, but not any that we can extract.) In fact, in the entire United States, there isn't much tritium at all, since your government considers this beta emitter - used on luminous watch dials - to be hazardous to your life. (Please be appreciative.)
Where would we get the tritium? I don't know, and I don't think anyone else does either. But there are other problems that I suspect are overwhelming in light of our present-day engineering and material capabilities - and may be physically impossible to solve. [For more on this subject, see the August 1999 edition of The Energy Advocate, published by Howard Hayden, professor emeritus of Physics, University of Connecticut. P.O. Box 7595, Pueblo West, CO 81007 - or www.EnergyAdvocate.com. ($35/year.)]
First, the energy required to magnetically contain the process (the only way it can be contained, since these temperatures decompose all materials into constituent atoms) invariably requires more energy than can be generated. Yet if, and when, this obstacle can be overcome, we have the problem of that pesky neutron.
While other particles can be redirected magnetically to where they have little danger to humans or equipment, the electrically neutral neutron has a mind of its own. When a plethora of neutrons are released around normal materials, those materials are transmuted into other element that are typically radioactive. Wouldn't this make the fusion reactor radioactive? Yes it would, which is probably why hot-fusion experiments reportedly must be cooled-down, dismantled, and decontaminated after every test run of only a few seconds. This might prompt us to ask, "What about the delivery of energy, twenty-four hours per day, 365 days per year?" There are, in my opinion, two choices.
Monday, April 4, 2016
Five Million Miles on a Pound of Plutonium?
In the early 1950s, when I was an almost-teenager reading all the popular magazines on science and mathematics I could read at the drugstore newsstand, there were articles on "atomic propulsion" for every conceivable vehicle from motorcycles to space ships. (Well, maybe not motorcycles.) A lot of the concepts were just that: concepts. Grandiose ideas sold magazines but would probably not have done much to power your fishing boat.
Only a few years later we learned the horrors of exposure to radiation. I can remember reading - even before age thirteen - not only the heart-rending stories of A-bomb victims, but also about the unfortunate Japanese fishermen who were accidentally exposed to H-bomb test fall-out. I thought they all had died. (Although billed by the press as "Lethally Exposed," except for the one who died from acute radiation sickness, none of the other twenty-two was a cancer fatality as of twenty-five yars after exposure.) [Kumatori, T. Ishihara, T., Hirshima, K., Sugiyama, H., Ishii, S., and Miyoshi, K. Follow-up studies over a twenty-five-year period on the Japanese fishermen exposed to radioactive fallout in 1954. The Medical Basis for Radiation Preparedness, Hubner, K.F., and Fry, A.A., editors, Elsevier, New York, 1980.]
It wasn't long after this that the "atomic power" articles, and much of the interest in nuclear technology, dried up. The Linear No-Threshold hypothesis was soon to send all of those ideas into the black hole of radiation avoidance - which later became radiation hysteria. Did we miss the "nuclear vehicle" boat because of our fears and the rules imposed on the nuclear industry? "What might have been" is truly an impossible question to answer. Thousands of independently acting entrepreneurs would have answered it for us, had they been given the chance.
Neither the pressurized water reactor (PWR) nor the boiling water reactor (BWR) - the mainstays of the U.S. nuclear power industry - are adaptable to smaller scale, mobile applications. A variation of the CANDU reactor principle would come closer by using low-boiling-point compounds such as CFCs to spin a turbine, but even that is a stretch for anything smaller than a large bus. (Not to say that it couldn't be done if technology is given a chance.)
But why worry about atomic-powered anythings? What we're currently using is working out pretty well, isn't it? True, but let's look for a moment at how we fuel our vehicles. And though I don't think we are in danger of "running out of oil" any time soon, it is logical to assume that the energy cost of obtaining oil will increase as the oil-bearing strata become more and more difficult to access.
If we take your politically incorrect sports utility vehicle out on the open road with one pound of gasoline in it, the heat energy content of the fuel will propel you about three miles. By comparison the heat energy in one pound of plutonium would take you some 5,420,000 miles down the road - using the same efficiency figure as the gasoline engine. [The efficiency would be lower using today's technology. But even at half or a quarter the already-low efficiencies of internal combustion engines, the incredible heat content of many radioactive isotopes makes for unbelievable comparisons to all fossil fuels.]
Since this is about thirty times more than the typical mechanical life of a vehicle, it is likely that any nuclear-powered vehicle would be fueled for life at the factory.
All well and good, you might say. But what about the lack of adaptability of power-plant technology to mobile vehicles? Good question. There are other nuclear technologies, besides trying to shrink a power plant, that would be interesting to explore. One of these is the radioisotope thermo-electric generator or RTG.
The RTG is based on a very simple physical principle known as thermoelectricity. ["Simple" in practice, as anyone can connect different types of wires together; the theory, known as the Seebeck effect, is a little more complicated.]
If you take two wires of different materials and connect their junctions in a loop, a current will flow when the temperature of the "hot junction" is greater than that of the "cold junction." In the RTG, a radioisotope supplies the heat, while a "heat sink" - such as you might find on the rear of a high-powered stereo amplifier - cools the cold junction. Any number of junctions can be connected in series (known as thermopile) to produce whatever voltage is desired, while connections are paralleled to increase the current flow. The inherent low voltage of the device can be increased with a dc-to-dc or dc-to-ac converter. [Transformers, used on alternating current circuits, do not work for direct current. A "dc-to-dc" converter chops the dc, making it appear to be ac, transforms it to a different voltage, and then rectifies it back to dc.]
An obvious advantage of the thermo-electric generator is its total lack of moving parts - since electrons don't count.
The Manhattan project scientists had inadvertently discovered this "warmness" of the plutonium 239 isotope. [Actually all radioactive isotopes generate heat as a byproduct of decay - but both the rate and the type of decay emissions are important. You really wouldn't want to cozy up with a strong gamma ray emitter.]
Project experimenters supposedly used the plutonium received from the Hanford reservation - gleaned and refined at an almost unbelievable price - as hand warmers. While alpha particles lose their energy too quickly to penetrate the skin, these atomic "shot-puts" collide with and agitate atoms with which they come in contact, hence the feeling of warmth.
As we might expect, the rate of decay of the isotope has much to do with an isotope's heat-producing potential. While bomb-grade plutonium 239 (with its 24,110-year half-life) is okay for hand warmers, another plutonium isotope (atomic weight 238, with a half-life of only 87.7 years) is the candidate of choice for our extraterrestrial deep-space probes. Plutonium 238 can really kick atoms around, to way beyond the boiling point of water. [Spacecraft power supplies operate at approximately 800 degrees Fahrenheit. RTG temperatures can exceed 1,300 degrees Fahrenheit.]
This is not new technology. All deep-space probes must have some sort of nuclear power supply, as none of the alternatives are able to supply usable amounts of power for the years it takes to complete these missions. Batteries are out of the question for even short missions, and solar panels don't work well, since the energy available drops off as the square of the distance from the sun. A ten-by-ten-foot collector for Earth-Moon operations, for instance, would swell to tennis court size for missions to Jupiter, and blossom to the equivalent of more than two football fields for exploration of Neptune. Moreover, Earth-based solar cells are not easy to mount efficiently, even with a solid terra firma foundation. How about trying to maneuver football-field sized collector banks - structures and deployment mechanisms - in a zero-gravity environment? [Fuel cells would be find, except that the weight of the fuel - and its containers - would't allow for much else on the voyage. We might want to note, thanks to the science eduation given by the mission and movie Apollo 13, most of us are now well aware that fuel cells must carry their own oxidizer - which, in the case of oxygen, was not readily available in interlunar space.]
While the RTG has been the only practical choice for deep-space missions, anti-nuclear propagandists have portrayed it as a hazard to the entire human race because of its use of plutonium fuel. The misguided protesters wring their hands over seventy-two pounds of plutonium that they contend might somehow be released into the atmosphere and over the effect that might have on humankind. However, they totally ignore the fact that two to three tons of various vaporized (and hence, breathable) plutonium isotopes were injected into the biosphere by the Nagasaki bomb and the hundreds of above-ground tests just after World War II; yet the last time I looked, the human race was still alive and kicking.
While spacecraft have shown the reliability and longevity of the RTG, why haven't there been applications in transportation utilizing this technology? [Another very successful use of the plutonium RTG was in pacemakers. From 1973 through 1987, 155 radioisotope-powered pacemakers were implanted in a Newark Beth Israel Medical Center study. With a half-life of eighty-seven years, the nuclear devices outlasted battery operated devices - which required surgery for re-implantation - by many years and were ultra-reliable. And although "it has been shown beyond any reasonable doubt that there is no increased risk of malignancy in this group of patients" few, if any, new nuclear devices are being installed. Why? It's our good friend, the Linear No-Threshold hypothesis. See "The Nuclear Pacemaker: Is Renewed Interest Warranted?" American Journal of Cardiology, Oct. 1990.]
It certainly doesn't require a rocket scientist to conceive of an RTG automobile that would have both a generator and auxiliary batteries available for acceleration and hills - yet would recharge itself, both while driving and while sitting all day in a parking lot. But if you remember the story about the Goianians, you may have already considered the possibility of being stoned whenever you pulled your Plutoniumobile out of the garage - not to mention having to deal with swarms of bureaucrats from every imaginable protective agency who would be on the spot to make sure no alpha ray is loosed on the public. With incentives like these for the buyer, entrepreneurs are not exactly standing in line to enter this market.
Want to get 5,420,000 miles to the pound? Me too. Sorry to say that's never going to happen, because the long-standing and difficult problem of squeezing actual energy from potential energy is fraught with some inconvenient impossibilities. But if we are to approach the theoretical limits of physical science, it will take an understanding of the real dangers of radiation, and getting the government out of the policing business. Plus, no doubt, many billions of dollars in research and development costs; but that's what capitalists do: invest their money to make profits from producing things that cause our lives to be more satisfying.
Oh, and not to worry. Manufacturers of nuclear-powered vehicles are not going to fry their customers with gamma rays any more than Campbell's would put botulin toxin in the soup.
It's not good for business.
Only a few years later we learned the horrors of exposure to radiation. I can remember reading - even before age thirteen - not only the heart-rending stories of A-bomb victims, but also about the unfortunate Japanese fishermen who were accidentally exposed to H-bomb test fall-out. I thought they all had died. (Although billed by the press as "Lethally Exposed," except for the one who died from acute radiation sickness, none of the other twenty-two was a cancer fatality as of twenty-five yars after exposure.) [Kumatori, T. Ishihara, T., Hirshima, K., Sugiyama, H., Ishii, S., and Miyoshi, K. Follow-up studies over a twenty-five-year period on the Japanese fishermen exposed to radioactive fallout in 1954. The Medical Basis for Radiation Preparedness, Hubner, K.F., and Fry, A.A., editors, Elsevier, New York, 1980.]
It wasn't long after this that the "atomic power" articles, and much of the interest in nuclear technology, dried up. The Linear No-Threshold hypothesis was soon to send all of those ideas into the black hole of radiation avoidance - which later became radiation hysteria. Did we miss the "nuclear vehicle" boat because of our fears and the rules imposed on the nuclear industry? "What might have been" is truly an impossible question to answer. Thousands of independently acting entrepreneurs would have answered it for us, had they been given the chance.
Neither the pressurized water reactor (PWR) nor the boiling water reactor (BWR) - the mainstays of the U.S. nuclear power industry - are adaptable to smaller scale, mobile applications. A variation of the CANDU reactor principle would come closer by using low-boiling-point compounds such as CFCs to spin a turbine, but even that is a stretch for anything smaller than a large bus. (Not to say that it couldn't be done if technology is given a chance.)
But why worry about atomic-powered anythings? What we're currently using is working out pretty well, isn't it? True, but let's look for a moment at how we fuel our vehicles. And though I don't think we are in danger of "running out of oil" any time soon, it is logical to assume that the energy cost of obtaining oil will increase as the oil-bearing strata become more and more difficult to access.
If we take your politically incorrect sports utility vehicle out on the open road with one pound of gasoline in it, the heat energy content of the fuel will propel you about three miles. By comparison the heat energy in one pound of plutonium would take you some 5,420,000 miles down the road - using the same efficiency figure as the gasoline engine. [The efficiency would be lower using today's technology. But even at half or a quarter the already-low efficiencies of internal combustion engines, the incredible heat content of many radioactive isotopes makes for unbelievable comparisons to all fossil fuels.]
Since this is about thirty times more than the typical mechanical life of a vehicle, it is likely that any nuclear-powered vehicle would be fueled for life at the factory.
All well and good, you might say. But what about the lack of adaptability of power-plant technology to mobile vehicles? Good question. There are other nuclear technologies, besides trying to shrink a power plant, that would be interesting to explore. One of these is the radioisotope thermo-electric generator or RTG.
The RTG is based on a very simple physical principle known as thermoelectricity. ["Simple" in practice, as anyone can connect different types of wires together; the theory, known as the Seebeck effect, is a little more complicated.]
If you take two wires of different materials and connect their junctions in a loop, a current will flow when the temperature of the "hot junction" is greater than that of the "cold junction." In the RTG, a radioisotope supplies the heat, while a "heat sink" - such as you might find on the rear of a high-powered stereo amplifier - cools the cold junction. Any number of junctions can be connected in series (known as thermopile) to produce whatever voltage is desired, while connections are paralleled to increase the current flow. The inherent low voltage of the device can be increased with a dc-to-dc or dc-to-ac converter. [Transformers, used on alternating current circuits, do not work for direct current. A "dc-to-dc" converter chops the dc, making it appear to be ac, transforms it to a different voltage, and then rectifies it back to dc.]
An obvious advantage of the thermo-electric generator is its total lack of moving parts - since electrons don't count.
The Manhattan project scientists had inadvertently discovered this "warmness" of the plutonium 239 isotope. [Actually all radioactive isotopes generate heat as a byproduct of decay - but both the rate and the type of decay emissions are important. You really wouldn't want to cozy up with a strong gamma ray emitter.]
Project experimenters supposedly used the plutonium received from the Hanford reservation - gleaned and refined at an almost unbelievable price - as hand warmers. While alpha particles lose their energy too quickly to penetrate the skin, these atomic "shot-puts" collide with and agitate atoms with which they come in contact, hence the feeling of warmth.
As we might expect, the rate of decay of the isotope has much to do with an isotope's heat-producing potential. While bomb-grade plutonium 239 (with its 24,110-year half-life) is okay for hand warmers, another plutonium isotope (atomic weight 238, with a half-life of only 87.7 years) is the candidate of choice for our extraterrestrial deep-space probes. Plutonium 238 can really kick atoms around, to way beyond the boiling point of water. [Spacecraft power supplies operate at approximately 800 degrees Fahrenheit. RTG temperatures can exceed 1,300 degrees Fahrenheit.]
This is not new technology. All deep-space probes must have some sort of nuclear power supply, as none of the alternatives are able to supply usable amounts of power for the years it takes to complete these missions. Batteries are out of the question for even short missions, and solar panels don't work well, since the energy available drops off as the square of the distance from the sun. A ten-by-ten-foot collector for Earth-Moon operations, for instance, would swell to tennis court size for missions to Jupiter, and blossom to the equivalent of more than two football fields for exploration of Neptune. Moreover, Earth-based solar cells are not easy to mount efficiently, even with a solid terra firma foundation. How about trying to maneuver football-field sized collector banks - structures and deployment mechanisms - in a zero-gravity environment? [Fuel cells would be find, except that the weight of the fuel - and its containers - would't allow for much else on the voyage. We might want to note, thanks to the science eduation given by the mission and movie Apollo 13, most of us are now well aware that fuel cells must carry their own oxidizer - which, in the case of oxygen, was not readily available in interlunar space.]
While the RTG has been the only practical choice for deep-space missions, anti-nuclear propagandists have portrayed it as a hazard to the entire human race because of its use of plutonium fuel. The misguided protesters wring their hands over seventy-two pounds of plutonium that they contend might somehow be released into the atmosphere and over the effect that might have on humankind. However, they totally ignore the fact that two to three tons of various vaporized (and hence, breathable) plutonium isotopes were injected into the biosphere by the Nagasaki bomb and the hundreds of above-ground tests just after World War II; yet the last time I looked, the human race was still alive and kicking.
While spacecraft have shown the reliability and longevity of the RTG, why haven't there been applications in transportation utilizing this technology? [Another very successful use of the plutonium RTG was in pacemakers. From 1973 through 1987, 155 radioisotope-powered pacemakers were implanted in a Newark Beth Israel Medical Center study. With a half-life of eighty-seven years, the nuclear devices outlasted battery operated devices - which required surgery for re-implantation - by many years and were ultra-reliable. And although "it has been shown beyond any reasonable doubt that there is no increased risk of malignancy in this group of patients" few, if any, new nuclear devices are being installed. Why? It's our good friend, the Linear No-Threshold hypothesis. See "The Nuclear Pacemaker: Is Renewed Interest Warranted?" American Journal of Cardiology, Oct. 1990.]
It certainly doesn't require a rocket scientist to conceive of an RTG automobile that would have both a generator and auxiliary batteries available for acceleration and hills - yet would recharge itself, both while driving and while sitting all day in a parking lot. But if you remember the story about the Goianians, you may have already considered the possibility of being stoned whenever you pulled your Plutoniumobile out of the garage - not to mention having to deal with swarms of bureaucrats from every imaginable protective agency who would be on the spot to make sure no alpha ray is loosed on the public. With incentives like these for the buyer, entrepreneurs are not exactly standing in line to enter this market.
Want to get 5,420,000 miles to the pound? Me too. Sorry to say that's never going to happen, because the long-standing and difficult problem of squeezing actual energy from potential energy is fraught with some inconvenient impossibilities. But if we are to approach the theoretical limits of physical science, it will take an understanding of the real dangers of radiation, and getting the government out of the policing business. Plus, no doubt, many billions of dollars in research and development costs; but that's what capitalists do: invest their money to make profits from producing things that cause our lives to be more satisfying.
Oh, and not to worry. Manufacturers of nuclear-powered vehicles are not going to fry their customers with gamma rays any more than Campbell's would put botulin toxin in the soup.
It's not good for business.
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.
Saturday, April 2, 2016
Energy: Don't Leave Home Without It
Did we miss the "nuclear vehicle" boat because of our fears and the rules imposed on the nuclear industry? "What might have been" is truly an impossible question to answer.
With the population of the Earth now surpassing 6 billion, and the requirement for energy per capita continually increasing as mankind is being liberated from the yoke, we can expect an exponential increase in the requirement for energy. Some of you believe that we need to limit the population of the world. I disagree - and if you're interested you can read a summary of my position in the footnote.
[Footnote: In the thousand years that the Earth had a low and "flat" population, the inhabitants suffered unbelievable deprivation by our standards. Today the population of the Earth and the standard of living are higher than ever. An unproductive person is indeed a drain on society; but, until government prevents it, more people are in productive activities than living off the productive.]
Some would fear that our unspoiled wilderness and irreplaceable wildlife will be destroyed if the population continues to grow. Again, I disagree, but go to the footnote only if this is of any interest to you.
[Footnote: If you want to see true environmental catastrophe, take a look at (a) the energy-impoverished countries were vegetation is stripped to the roots as a source of cooking fuel and tribesmen must spend most of their day's energy output in foraging for firewood, or (b) the Eastern-bloc countries, where almost an entire continent would be declared a Superfund site under our system. And you might note that only those creatures that are "owned by all of us" are in danger. Species in private hands do quite well.]
Regardless of what you believe, the odds are in favor of a continued growth with these trends predominating. So what are to be the energy sources in the future?
Many environmentalists are excited about solar power. How can you blame them? It's everywhere - and it's free. But there are a few other considerations. While many low-powered applications are feasible, when it comes down to commercial and industrial applications, solar energy becomes pretty darn environmentally hostile. A fairly modest eight- or nine-story suburban office building might require a megawatt of electrical energy at its peak monthly need. The dedicated solar energy plant - with 10% efficiency (not yet attainable), a 50% collector spacing, and a load factor of 75% (it must be able to supply 75% of the maximum load at any time) - required to support this building situated on less than one acre of ground, would need approximately 100 to 300 acres of collection and storage (battery) space, depending on climate. Energy-intensive industrial plants could easily require 500 to 1,000 acres of solar facility for each factory acre. Just as it would be a lovely thing to have a solar-powered car like those that race on the Australian desert (in the daytime), it is just a crying shame that the sun doesn't supply more than one kilowatt per square meter anywhere on Earth.
Wind energy has such obvious problems with availability - in addition to being very insensitive to passing birds and eerily noisy to nearby residents - that it really can't qualify as a reliable source. And while hydroelectric power is a wonderful thing (until the dam silts up), there are only a limited number of sites in the United States with any real energy potential. Imagine, if you will, trying to build a hydroelectric dam in Florida or southern Louisiana, and you'll get the idea. I'm not even going to discuss chicken manure or geothermal energy. If you're hanging your hat on these, you're obviously in the wrong book.
With the population of the Earth now surpassing 6 billion, and the requirement for energy per capita continually increasing as mankind is being liberated from the yoke, we can expect an exponential increase in the requirement for energy. Some of you believe that we need to limit the population of the world. I disagree - and if you're interested you can read a summary of my position in the footnote.
[Footnote: In the thousand years that the Earth had a low and "flat" population, the inhabitants suffered unbelievable deprivation by our standards. Today the population of the Earth and the standard of living are higher than ever. An unproductive person is indeed a drain on society; but, until government prevents it, more people are in productive activities than living off the productive.]
Some would fear that our unspoiled wilderness and irreplaceable wildlife will be destroyed if the population continues to grow. Again, I disagree, but go to the footnote only if this is of any interest to you.
[Footnote: If you want to see true environmental catastrophe, take a look at (a) the energy-impoverished countries were vegetation is stripped to the roots as a source of cooking fuel and tribesmen must spend most of their day's energy output in foraging for firewood, or (b) the Eastern-bloc countries, where almost an entire continent would be declared a Superfund site under our system. And you might note that only those creatures that are "owned by all of us" are in danger. Species in private hands do quite well.]
Regardless of what you believe, the odds are in favor of a continued growth with these trends predominating. So what are to be the energy sources in the future?
Many environmentalists are excited about solar power. How can you blame them? It's everywhere - and it's free. But there are a few other considerations. While many low-powered applications are feasible, when it comes down to commercial and industrial applications, solar energy becomes pretty darn environmentally hostile. A fairly modest eight- or nine-story suburban office building might require a megawatt of electrical energy at its peak monthly need. The dedicated solar energy plant - with 10% efficiency (not yet attainable), a 50% collector spacing, and a load factor of 75% (it must be able to supply 75% of the maximum load at any time) - required to support this building situated on less than one acre of ground, would need approximately 100 to 300 acres of collection and storage (battery) space, depending on climate. Energy-intensive industrial plants could easily require 500 to 1,000 acres of solar facility for each factory acre. Just as it would be a lovely thing to have a solar-powered car like those that race on the Australian desert (in the daytime), it is just a crying shame that the sun doesn't supply more than one kilowatt per square meter anywhere on Earth.
Wind energy has such obvious problems with availability - in addition to being very insensitive to passing birds and eerily noisy to nearby residents - that it really can't qualify as a reliable source. And while hydroelectric power is a wonderful thing (until the dam silts up), there are only a limited number of sites in the United States with any real energy potential. Imagine, if you will, trying to build a hydroelectric dam in Florida or southern Louisiana, and you'll get the idea. I'm not even going to discuss chicken manure or geothermal energy. If you're hanging your hat on these, you're obviously in the wrong book.
Friday, April 1, 2016
SECURE and the IFR
Other low-temperature reactors - used for warming entire communities - are not new to the world... just to U.S. citizens with our abysmal lack of scientific knowledge. For instance, a Swedish and Finnish consortium has designed a 200 MW inherently safe reactor called SECURE - with no moving parts, not even control rods - as the reactivity level is controlled by the content of boric acid in the coolant/moderator. [Safe and Environmentally Clean Urban REactor]
Finally, there is another reactor design known as the Integral Fast Reactor, which I find fascinating, because it is fueled by natural uranium and is as close to a perpetual motion machine as we are likely to get. [See Integral Fast Reactor, available from Argonne National Laboratories, P.O. Box 2528, Idaho Falls, ID 83415.]
It operates in a vessel filled with liquid sodium (melting point, 208 degrees Fahrenheit), which is a much better heat-transfer agent than water - along with having certain desirable nuclear characteristics. It reportedly produces 100 to 200 times more electrical energy per pound of fuel than obtainable from existing plants. The prototype plant, at Idaho Falls, was designed to be virtually self-contained with the capability of fabricating, using and reprocessing the spent fuel "on-site." It is inherently safe from a meltdown, since the fuel assemblies are configured in such a manner as to shut down the reaction when the temperature increases above its maximum design point. As a test, the entire heat transfer system was shut down while operating at full power - without causing any harm to the reactor.
While it is unlikely that the fuel-processing part of the operation could be scaled down to community or residential proportions, the inherent safety of the reactor is intriguing, along with its use of natural (unenriched) uranium. It is likely that radiation would be an insignificant factor compared with keeping the sodium contained, since contact with either water or air causes some pretty nasty chemical reactions. (It is best kept submerged in kerosene or naphtha.)
As far as I know, a low-power, inherently safe reactor has not been designed for community or home use. Why? I suspect it's because the prevailing fear of low-level radiation would keep any reasonably intelligent investor in the "sow bellies futures" market where at least there is a chance of making a profit. Why design a product that will cost more in attorneys' fees each time you sell one than the sale price of the product itself? Although much of the technology is there and proven, it just won't happen in today's climate ruled by the Linear No-Threshold bureaucracy.
But if we can create an understanding of actual - as opposed to perceived - radiation dangers, the technology will surely flourish. Because of higher efficiencies? No, large power reactors operating at high temperatures have higher efficiencies than would a home or community reactor and are well suited for commercial and industrial power production - but they also have transmission losses, transformer losses, costs of installing and maintaining pole-line hardware, and other overhead expenses that can be eliminated by decentralization, especially for small, off-the-beaten-path residential customers who use only a few thousand kilowatt-hours per month.
Would we require a government program to make this happen? Not at all. Just get the government out of the way, and let market forces determine what is worthy and what is not. As Paul Johnson put it: "For capitalism merely occurs, if no one does anything to stop it. It is socialism that has to be constructed, and as a rule, forcibly imposed, thus providing a far bigger role for intellectuals in its genesis." ["The heartless loves of humankind," Wall Street Journal, January 5, 1987.]
Finally, there is another reactor design known as the Integral Fast Reactor, which I find fascinating, because it is fueled by natural uranium and is as close to a perpetual motion machine as we are likely to get. [See Integral Fast Reactor, available from Argonne National Laboratories, P.O. Box 2528, Idaho Falls, ID 83415.]
It operates in a vessel filled with liquid sodium (melting point, 208 degrees Fahrenheit), which is a much better heat-transfer agent than water - along with having certain desirable nuclear characteristics. It reportedly produces 100 to 200 times more electrical energy per pound of fuel than obtainable from existing plants. The prototype plant, at Idaho Falls, was designed to be virtually self-contained with the capability of fabricating, using and reprocessing the spent fuel "on-site." It is inherently safe from a meltdown, since the fuel assemblies are configured in such a manner as to shut down the reaction when the temperature increases above its maximum design point. As a test, the entire heat transfer system was shut down while operating at full power - without causing any harm to the reactor.
While it is unlikely that the fuel-processing part of the operation could be scaled down to community or residential proportions, the inherent safety of the reactor is intriguing, along with its use of natural (unenriched) uranium. It is likely that radiation would be an insignificant factor compared with keeping the sodium contained, since contact with either water or air causes some pretty nasty chemical reactions. (It is best kept submerged in kerosene or naphtha.)
As far as I know, a low-power, inherently safe reactor has not been designed for community or home use. Why? I suspect it's because the prevailing fear of low-level radiation would keep any reasonably intelligent investor in the "sow bellies futures" market where at least there is a chance of making a profit. Why design a product that will cost more in attorneys' fees each time you sell one than the sale price of the product itself? Although much of the technology is there and proven, it just won't happen in today's climate ruled by the Linear No-Threshold bureaucracy.
But if we can create an understanding of actual - as opposed to perceived - radiation dangers, the technology will surely flourish. Because of higher efficiencies? No, large power reactors operating at high temperatures have higher efficiencies than would a home or community reactor and are well suited for commercial and industrial power production - but they also have transmission losses, transformer losses, costs of installing and maintaining pole-line hardware, and other overhead expenses that can be eliminated by decentralization, especially for small, off-the-beaten-path residential customers who use only a few thousand kilowatt-hours per month.
Would we require a government program to make this happen? Not at all. Just get the government out of the way, and let market forces determine what is worthy and what is not. As Paul Johnson put it: "For capitalism merely occurs, if no one does anything to stop it. It is socialism that has to be constructed, and as a rule, forcibly imposed, thus providing a far bigger role for intellectuals in its genesis." ["The heartless loves of humankind," Wall Street Journal, January 5, 1987.]
Thursday, March 31, 2016
CANDU and SLOWPOKE
While the United States - with its post-World War II enrichment technology and capacity - built power reactors using enriched uranium, the Canadians took a different approach. You may recall that deuterium (2H) reacts with oxygen to form "heavy water" - an unusually good moderator that bounces back and slows down neutrons that might ordinarily escape the reactor. The most interesting thing about the Canadian CANDU heavy water reactor - from the standpoint of community or home power plants - is that it uses natural (unenriched) uranium. This doesn't get them off the hook from an initial energy expenditure, however, since heavy water is expensive to separate - about $100 per pound and costing $100 million dollars for a full-scale 1,000 megawatt reactor. It does, however, eliminate the problem of enrichment. The CANDU design has many parallel fuel assemblies with the heavy water coolant/moderator flowing through each. To refuel the reactor, it doesn't need to be shut down; you just cut off the water to stop the nuclear reaction in a section isolated for refueling, and then change out the "spent" fuel assemblies.
["Spent" fuel assemblies aren't really spent at all - they have more than 95% of the initial fuel remaining with only a few percent of "daughters" that contaminate the rest and absorb the needed neutrons.]
Even more interesting from the standpoint of decentralization is the Canadian SLOWPOKE reactor, which is as safe and secure as a Sierra Club official working for the Environmental Protection Agency. [Safe LOW POwer Kritical Experiment - but it's not experimental anymore, having been in operation for more than twenty-five years. (Canadians may be great reactor designers, but they seem to have a little problem with their spelling.)]
Figure 34 shows a cutaway sketch of this "pool" type reactor - so named because it operates submerged in a pool of water. Unlike PWRs and BWRs, it does not have "defense in depth" - because it doesn't need it. The laws of physics provide it with more than enough protection.
The original design has a maximum operating temperature of 80 degrees Celsius with a cylindrical core about nine inches in diameter by nine inches in height. Surrounding the enriched-uranium fuel assembly are beryllium reflectors, which keep the reactor critical... as long as the water density remains high. If the reactor "heats up," the lower water density slows the reaction bringing the temperature back to the design point. [SLOWPOKE I and II have been operational for some time; the series is now up to V or VI, but I haven't been able to get much information on the later models.]
Suppose all the water evaporates or is sloshed out by an earthquake? Naturally, the reaction stops, as the moderator is gone. But also the power density is so low that nothing happens to the fuel. The reactor just goes dormant until someone takes an action to bring it back to life. [Typically the operators do not have access to the reactor.]
As Canadian scientist Dr. John Hilborn, who conducted experiments leading to the SLOWPOKE, said, "It is safer without operators than with them." [From an interview with Petr Beckmann, Access to Energy, Vol. 8, No. 9, May 1981, pp. 1-2.]
The original SLOWPOKEs were not designed as power reactors. Their heat output (which is considerably higher than any possible electrical output) is a mere twenty kilowatts, equivalent to about thirteen hair dryers. Their function, as mentioned, was not to produce electricity but to transmute certain materials into radionuclides, primarily for medical purposes. But the concept of a low-temperature, inherently safe, non-polluting, inexpensive-to-fuel, produce-power-where-you-need-it reactor is intriguing for those who would like to have energy independence. [Some electric utilities might oppose such a competitive concept, but they would, as mentioned, be in the best position to provide service for local power reactors.]
["Spent" fuel assemblies aren't really spent at all - they have more than 95% of the initial fuel remaining with only a few percent of "daughters" that contaminate the rest and absorb the needed neutrons.]
Even more interesting from the standpoint of decentralization is the Canadian SLOWPOKE reactor, which is as safe and secure as a Sierra Club official working for the Environmental Protection Agency. [Safe LOW POwer Kritical Experiment - but it's not experimental anymore, having been in operation for more than twenty-five years. (Canadians may be great reactor designers, but they seem to have a little problem with their spelling.)]
Figure 34 shows a cutaway sketch of this "pool" type reactor - so named because it operates submerged in a pool of water. Unlike PWRs and BWRs, it does not have "defense in depth" - because it doesn't need it. The laws of physics provide it with more than enough protection.
The original design has a maximum operating temperature of 80 degrees Celsius with a cylindrical core about nine inches in diameter by nine inches in height. Surrounding the enriched-uranium fuel assembly are beryllium reflectors, which keep the reactor critical... as long as the water density remains high. If the reactor "heats up," the lower water density slows the reaction bringing the temperature back to the design point. [SLOWPOKE I and II have been operational for some time; the series is now up to V or VI, but I haven't been able to get much information on the later models.]
Suppose all the water evaporates or is sloshed out by an earthquake? Naturally, the reaction stops, as the moderator is gone. But also the power density is so low that nothing happens to the fuel. The reactor just goes dormant until someone takes an action to bring it back to life. [Typically the operators do not have access to the reactor.]
As Canadian scientist Dr. John Hilborn, who conducted experiments leading to the SLOWPOKE, said, "It is safer without operators than with them." [From an interview with Petr Beckmann, Access to Energy, Vol. 8, No. 9, May 1981, pp. 1-2.]
The original SLOWPOKEs were not designed as power reactors. Their heat output (which is considerably higher than any possible electrical output) is a mere twenty kilowatts, equivalent to about thirteen hair dryers. Their function, as mentioned, was not to produce electricity but to transmute certain materials into radionuclides, primarily for medical purposes. But the concept of a low-temperature, inherently safe, non-polluting, inexpensive-to-fuel, produce-power-where-you-need-it reactor is intriguing for those who would like to have energy independence. [Some electric utilities might oppose such a competitive concept, but they would, as mentioned, be in the best position to provide service for local power reactors.]
Wednesday, March 30, 2016
Power Reactors
In the United States, power reactors are entirely of the PWR (pressurized water reactor) or the BWR (boiling water reactor) types. In both cases, water is used as the coolant and the moderator, which provides a very interesting advantage that probably no one has bothered to mention to you: If the coolant is lost, the chain reaction stops. Depending on the length of time the fuel has been producing power, the fuel rods may or may not be thermally and radioactively "hot" from the daughters of the fissioning process. Even in the worst case, the heat generated is no more than 1% or 2% of that during normal operation. This is why the "disaster" at Three Mile Island didn't really happen - except in the minds of the uninformed.
While the Japanese installed the first Advanced Boiling Water Reactor (ABWR) in 1996, none of the new, modular designs have seen the light of day in this country. Not only have we been blinded by the non-threat of low-level radiation, but the cost of building a nuclear plant has escalated by a factor of seventeen, after considering inflation - mostly from construction delays caused by environmentalist lawsuits. (The above-mentioned Japanese ABSR plant took fifty-two months to build - compared with more than eleven years for the most recent plant in the United States.) I would say the new designs are even safer than the old - but how do you get safer than no deaths, no injuries, and no negative effects to the public from several thousand reactor years of operation with thousands of gigawatt-hours of life-enhancing electrical energy having been generated? [Some of the media scream "disaster" when ten gallons of water with 1/80 the radioactivity of salad oil leak out in the process of heating and otherwise providing life-giving energy to an entire city. Why doesn't it make front-page news when some one falls off the roof to his death trying to clean the solar collector - which provides a few puny kilowatts of solar energy for warming the hot water... when the sun is shining?]
Nonetheless, neither the PWR or BWR has much promise for miniaturization and "local" use as - by nature - they operate with high-power densities, which have the potential to cause a messy and expensive loss-of-coolant accident. They also require pumps, back-up pumps, and relatively elaborate controls.
All of these U.S. power reactors use enriched uranium as a fuel, as do reactors in France (where 80% of the electrical power comes from nuclear energy), Japan, England, and most other countries. The enrichment process starts with natural uranium, which is dissolved in acid to produce uranium hexafluoride gas. This ultra-corrosive gas is then pumped thousands of times through membranes where the lighter U235 passes through just a little bit easier than the U238. For power reactors, the U235 is enriched from 0.7% to about 3.5%, which takes not only lots of time but considerable energy. ["Bomb grade" U235 must be enriched to 90% - an extremely difficult process. Thank goodness, or any crackpot might be able to do it.)]
While the Japanese installed the first Advanced Boiling Water Reactor (ABWR) in 1996, none of the new, modular designs have seen the light of day in this country. Not only have we been blinded by the non-threat of low-level radiation, but the cost of building a nuclear plant has escalated by a factor of seventeen, after considering inflation - mostly from construction delays caused by environmentalist lawsuits. (The above-mentioned Japanese ABSR plant took fifty-two months to build - compared with more than eleven years for the most recent plant in the United States.) I would say the new designs are even safer than the old - but how do you get safer than no deaths, no injuries, and no negative effects to the public from several thousand reactor years of operation with thousands of gigawatt-hours of life-enhancing electrical energy having been generated? [Some of the media scream "disaster" when ten gallons of water with 1/80 the radioactivity of salad oil leak out in the process of heating and otherwise providing life-giving energy to an entire city. Why doesn't it make front-page news when some one falls off the roof to his death trying to clean the solar collector - which provides a few puny kilowatts of solar energy for warming the hot water... when the sun is shining?]
Nonetheless, neither the PWR or BWR has much promise for miniaturization and "local" use as - by nature - they operate with high-power densities, which have the potential to cause a messy and expensive loss-of-coolant accident. They also require pumps, back-up pumps, and relatively elaborate controls.
All of these U.S. power reactors use enriched uranium as a fuel, as do reactors in France (where 80% of the electrical power comes from nuclear energy), Japan, England, and most other countries. The enrichment process starts with natural uranium, which is dissolved in acid to produce uranium hexafluoride gas. This ultra-corrosive gas is then pumped thousands of times through membranes where the lighter U235 passes through just a little bit easier than the U238. For power reactors, the U235 is enriched from 0.7% to about 3.5%, which takes not only lots of time but considerable energy. ["Bomb grade" U235 must be enriched to 90% - an extremely difficult process. Thank goodness, or any crackpot might be able to do it.)]
Tuesday, March 29, 2016
Mankind and Energy
The history of mankind is, in large part, a history of the harnessing of energy sources. Prehistoric man had only his own muscle power to wrest a livable habitat from his rugged environment. The discovery and control of fire eventually yielded metals, which improved the efficiency of muscle power and allowed the practical cultivation of crops. Domestication of animals - the horse, ox, donkey, elephant, dog - multiplied the energies of a man by severalfold. And this is where mankind remained for several thousand years.
While water wheels were used by several cultures for irrigation, the harnessing of hydropower was the product of the Industrial Revolution in mid-eighteenth-century England. The windmill was another attempt by man to increase his energy - one which is still going on, and still has the problem (as does hydropower) of requiring the cooperation of nature to utilize energy from the sun. (Both hydro and wind power are actually forms of solar energy, as are fossil fuels; but wood, coal, oil and natural gas don't require quite as much cooperation from nature.)
Man's (and beast's) burden was lessened immeasurably by English engineer Thomas Savery who, in 1698, invented the "fire engine" to pump water from mines. Thomas Newcomen in 1705 and James Watt in 1763 improved the design to where the steam engine could be used for a variety of purposes, including transportation.
As the Industrial Revolution moved east to the continent, so did the desire for ways to deliver more energy - with less human and animal effort. Frenchman Jean Joseph Etienne Lenoir is credited with building the first gasoline internal combustion engine in 1860, while German Rudolf Diesel patented his engine in 1892 (and mysteriously disappeared from a London-bound German ship just prior to World War I). The late nineteenth century saw the discovery and application of electrical principles by Dane Oersted, Frenchman Ampere, German Ohm, Englishman Faraday, American Henry, and Scotsman Maxwell - thus allowing energy to be transmitted from point of generation to point of need.
If we track both population and energy availability, we see that there has been a sixtyfold increase in industrialized countries since Savery (compared with a world population that had been constant for a thousand years) and the same order of magnitude of energy usage per capita. [Aren't you glad? - or there would be only a 1.6% chance that you would be here.] But today, we have reached a plateau.
While water wheels were used by several cultures for irrigation, the harnessing of hydropower was the product of the Industrial Revolution in mid-eighteenth-century England. The windmill was another attempt by man to increase his energy - one which is still going on, and still has the problem (as does hydropower) of requiring the cooperation of nature to utilize energy from the sun. (Both hydro and wind power are actually forms of solar energy, as are fossil fuels; but wood, coal, oil and natural gas don't require quite as much cooperation from nature.)
Man's (and beast's) burden was lessened immeasurably by English engineer Thomas Savery who, in 1698, invented the "fire engine" to pump water from mines. Thomas Newcomen in 1705 and James Watt in 1763 improved the design to where the steam engine could be used for a variety of purposes, including transportation.
As the Industrial Revolution moved east to the continent, so did the desire for ways to deliver more energy - with less human and animal effort. Frenchman Jean Joseph Etienne Lenoir is credited with building the first gasoline internal combustion engine in 1860, while German Rudolf Diesel patented his engine in 1892 (and mysteriously disappeared from a London-bound German ship just prior to World War I). The late nineteenth century saw the discovery and application of electrical principles by Dane Oersted, Frenchman Ampere, German Ohm, Englishman Faraday, American Henry, and Scotsman Maxwell - thus allowing energy to be transmitted from point of generation to point of need.
If we track both population and energy availability, we see that there has been a sixtyfold increase in industrialized countries since Savery (compared with a world population that had been constant for a thousand years) and the same order of magnitude of energy usage per capita. [Aren't you glad? - or there would be only a 1.6% chance that you would be here.] But today, we have reached a plateau.
Monday, March 28, 2016
Under the Grandstand
The first man-made chain reaction occurred under the grandstand of the University of Chicago football field on December 2, 1942, in what was known as an atomic "pile." It was so named because it was constructed of a "pile" of 45,000 high-purity graphite bricks (250 tons), with 19,000 drilled holes to contain the approximately 93,000 pounds of uranium metal and uranium oxide along with the cadmium control rods. When operating at its design point, it generated a half watt of power - enough to almost power a pencil sharpener. (Fortunately, it was not designed as a power reactor, but as an experiment to prove the "chain reaction" hypothesis.)
Why the "high-purity graphite bricks?" It has to do with the statement a few paragraphs back about "... if the energy of the neutron is within a certain range." When we want to make little rocks out of big rocks, we are accustomed to using a bigger hammer and swinging hard. Not so in the nuclear world. In order for a neutron to have a decent chance at fissioning a U235 nucleus, it must be slowed down by the action of a moderator. Carbon - as long as it is of high enough purity to avoid absorbing the neutrons - is a good moderator, although, as Chernobyl demonstrated, it has a few potential problems - which is why U.S. power reactors never use this material... or this type of "graphite reactor." It is typically used in military reactors for the production of plutonium - which reportedly was one of Chernobyl's functions, in addition to generating power. [Other uses would be in research reactors, as well as in reactors for use in creating medical radionuclides.]
Footnote to chapter: There is much evidence that a natural reactor "happened" in Western Africa in the Republic of Gabon at Oklo some 1.7 billion years ago when the ratio of U235 to U238 was considerably higher. It appears to have operated in accordance with the Nuclear Regulatory Commission rules of that time and was safely shut down after several hundred thousand years of operation. See Oklo Reactor, Scientific American, August 1976.
Why the "high-purity graphite bricks?" It has to do with the statement a few paragraphs back about "... if the energy of the neutron is within a certain range." When we want to make little rocks out of big rocks, we are accustomed to using a bigger hammer and swinging hard. Not so in the nuclear world. In order for a neutron to have a decent chance at fissioning a U235 nucleus, it must be slowed down by the action of a moderator. Carbon - as long as it is of high enough purity to avoid absorbing the neutrons - is a good moderator, although, as Chernobyl demonstrated, it has a few potential problems - which is why U.S. power reactors never use this material... or this type of "graphite reactor." It is typically used in military reactors for the production of plutonium - which reportedly was one of Chernobyl's functions, in addition to generating power. [Other uses would be in research reactors, as well as in reactors for use in creating medical radionuclides.]
Footnote to chapter: There is much evidence that a natural reactor "happened" in Western Africa in the Republic of Gabon at Oklo some 1.7 billion years ago when the ratio of U235 to U238 was considerably higher. It appears to have operated in accordance with the Nuclear Regulatory Commission rules of that time and was safely shut down after several hundred thousand years of operation. See Oklo Reactor, Scientific American, August 1976.
Sunday, March 27, 2016
Enter the Atom
Let's return for a short graduate course from Hormesis U. about "splitting the atom."
We've already seen that U238 is an isotope of uranium with a half-life of 4.5 billion years. [I realize I said I was going to refer to isotopes in the form of 238U or uranium 238. But U235 and U238 are such commonly used abbreviations to denote these isotopes that I will be using them in this chapter.]
With a lump of this element and the proper instruments, you would find there is another isotope, U235, which amounts to only 0.7% of the total mass. Yet it is this tiny fraction that makes uranium the tremendous source of safe and reliable energy - not to mention the fearful master - that it has become.
U235, like its more plentiful sibling, is an alpha emitter - but has a considerably shorter half-life... a mere 3,800,000 years, meaning that it was considerably more plentiful a billion or so years ago. [U235 is sometimes referred to as "actinium" or "uranoactinium."] It, along with plutonium 239 and U233, are the only isotopes that are fissionable - a phenomenon described below.
Under normal conditions, we can expect to see a U235 atom occasionally decay into an isotope of thorium and a helium nucleus (an alpha particle) similar to all radioactive isotopes experiencing alpha decay. ["Occasionally" takes on a new meaning in the atomic world. Our roughly penny-sized gram of U235 would experience approximately 80,000 nuclear disintegrations per second.]
But let us suppose that a stray neutron smacks into the nucleus of an unsuspecting U235 atom. If the energy of the neutron is within a certain range, our U235 target atom fissions, that is, breaks into pieces. [This was first observed by an unbelieving Lise Meitner in December 1938. She had observed barium, with an atomic number of 56, arising when she bombarded "actinium" with neutrons.]
It usually splits into two roughly equal parts, and most important, ejects about two neutrons. Obviously no atom could eject or emit about two neutrons, but, on average, that is what a fissioning U235 atom sends out of its nucleus.
Imagine, then, one of these neutrons hitting another U235 atom, which emits two neutrons with at least one of these splitting another atom... and so on, and so on. As you have no doubt already figured out, this is what is known as a chain reaction. When the ratio of fissioned atoms in successive generations is equal to one - that is, when one splitting atom causes exactly one more to split - the reaction is said to go critical. What happens to the other neutrons? They either escape from the volume of uranium, or they are absorbed - either unintentionally by structural material, or purposely by control rods made of boron, aluminum, cadmium, or several other neutron-absorbing materials - in order to keep the reaction under control (that is, to keep it from going super-critical). Does a super-critical reaction cause a bomb-like explosion? Not at all; if it did, bomb development by the Manhattan project would have been relatively simple rather than requiring the best theoretical physics minds on two continents. But super-criticality is no picnic. It causes rapid rises in fission reactions, leading to very high temperatures that cause structural damage, torrents of neutrons, and "steam explosions." Bad, yes, but still light years away from the mushroom-shaped cloud.
Let's look at a few different types of reactors, with an eye for those that might allow decentralization of electric power generation.
We've already seen that U238 is an isotope of uranium with a half-life of 4.5 billion years. [I realize I said I was going to refer to isotopes in the form of 238U or uranium 238. But U235 and U238 are such commonly used abbreviations to denote these isotopes that I will be using them in this chapter.]
With a lump of this element and the proper instruments, you would find there is another isotope, U235, which amounts to only 0.7% of the total mass. Yet it is this tiny fraction that makes uranium the tremendous source of safe and reliable energy - not to mention the fearful master - that it has become.
U235, like its more plentiful sibling, is an alpha emitter - but has a considerably shorter half-life... a mere 3,800,000 years, meaning that it was considerably more plentiful a billion or so years ago. [U235 is sometimes referred to as "actinium" or "uranoactinium."] It, along with plutonium 239 and U233, are the only isotopes that are fissionable - a phenomenon described below.
Under normal conditions, we can expect to see a U235 atom occasionally decay into an isotope of thorium and a helium nucleus (an alpha particle) similar to all radioactive isotopes experiencing alpha decay. ["Occasionally" takes on a new meaning in the atomic world. Our roughly penny-sized gram of U235 would experience approximately 80,000 nuclear disintegrations per second.]
But let us suppose that a stray neutron smacks into the nucleus of an unsuspecting U235 atom. If the energy of the neutron is within a certain range, our U235 target atom fissions, that is, breaks into pieces. [This was first observed by an unbelieving Lise Meitner in December 1938. She had observed barium, with an atomic number of 56, arising when she bombarded "actinium" with neutrons.]
It usually splits into two roughly equal parts, and most important, ejects about two neutrons. Obviously no atom could eject or emit about two neutrons, but, on average, that is what a fissioning U235 atom sends out of its nucleus.
Imagine, then, one of these neutrons hitting another U235 atom, which emits two neutrons with at least one of these splitting another atom... and so on, and so on. As you have no doubt already figured out, this is what is known as a chain reaction. When the ratio of fissioned atoms in successive generations is equal to one - that is, when one splitting atom causes exactly one more to split - the reaction is said to go critical. What happens to the other neutrons? They either escape from the volume of uranium, or they are absorbed - either unintentionally by structural material, or purposely by control rods made of boron, aluminum, cadmium, or several other neutron-absorbing materials - in order to keep the reaction under control (that is, to keep it from going super-critical). Does a super-critical reaction cause a bomb-like explosion? Not at all; if it did, bomb development by the Manhattan project would have been relatively simple rather than requiring the best theoretical physics minds on two continents. But super-criticality is no picnic. It causes rapid rises in fission reactions, leading to very high temperatures that cause structural damage, torrents of neutrons, and "steam explosions." Bad, yes, but still light years away from the mushroom-shaped cloud.
Let's look at a few different types of reactors, with an eye for those that might allow decentralization of electric power generation.
Saturday, March 26, 2016
Mankind and Energy
The history of mankind is, in large part, a history of the harnessing of energy sources. Prehistoric man had only his own muscle power to wrest a livable habitat from his rugged environment. The discovery and control of fire eventually yielded metals, which improved the efficiency of muscle power and allowed the practical cultivation of crops. Domestication of animals - the horse, ox, donkey, elephant, dog - multiplied the energies of a man by severalfold. And this is where mankind remained for several thousand years.
While water wheels were used by several cultures for irrigation, the harnessing of hydropower was the product of the Industrial Revolution in mid-eighteenth-century England. The windmill was another attempt by man to increase his energy - one which is still going on, and still has the problem (as does hydropower) of requiring the cooperation of nature to utilize energy from the sun. (Both hydro and wind power are actually forms of solar energy, as are fossil fuels; but wood, coal, oil and natural gas don't require quite as much cooperation from nature.)
Man's (and beast's) burden was lessened immeasurably by English engineer Thomas Savery who, in 1698, invented the "fire engine" to pump water from mines. Thomas Newcomen in 1705 and James Watt in 1763 improved the design to where the steam engine could be used for a variety of purposes, including transportation.
As the Industrial Revolution moved east to the continent, so did the desire for ways to deliver more energy - with less human and animal effort. Frenchman Jean Joseph Etienne Lenoir is credited with building the first gasoline internal combustion engine in 1860, while German Rudolf Diesel patented his engine in 1892 (and mysteriously disappeared from a London-bound German ship just prior to World War I). The late nineteenth century saw the discovery and application of electrical principles by Dane Oersted, Frenchman Ampere, German Ohm, Englishman Faraday, American Henry, and Scotsman Maxwell - thus allowing energy to be transmitted from point of generation to point of need.
If we track both population and energy availability, we see that there has been a sixtyfold increase in industrialized countries since Savery (compared with a world population that had been constant for a thousand years) and the same order of magnitude of energy usage per capita. But today, we have reached a plateau.
While water wheels were used by several cultures for irrigation, the harnessing of hydropower was the product of the Industrial Revolution in mid-eighteenth-century England. The windmill was another attempt by man to increase his energy - one which is still going on, and still has the problem (as does hydropower) of requiring the cooperation of nature to utilize energy from the sun. (Both hydro and wind power are actually forms of solar energy, as are fossil fuels; but wood, coal, oil and natural gas don't require quite as much cooperation from nature.)
Man's (and beast's) burden was lessened immeasurably by English engineer Thomas Savery who, in 1698, invented the "fire engine" to pump water from mines. Thomas Newcomen in 1705 and James Watt in 1763 improved the design to where the steam engine could be used for a variety of purposes, including transportation.
As the Industrial Revolution moved east to the continent, so did the desire for ways to deliver more energy - with less human and animal effort. Frenchman Jean Joseph Etienne Lenoir is credited with building the first gasoline internal combustion engine in 1860, while German Rudolf Diesel patented his engine in 1892 (and mysteriously disappeared from a London-bound German ship just prior to World War I). The late nineteenth century saw the discovery and application of electrical principles by Dane Oersted, Frenchman Ampere, German Ohm, Englishman Faraday, American Henry, and Scotsman Maxwell - thus allowing energy to be transmitted from point of generation to point of need.
If we track both population and energy availability, we see that there has been a sixtyfold increase in industrialized countries since Savery (compared with a world population that had been constant for a thousand years) and the same order of magnitude of energy usage per capita. But today, we have reached a plateau.
Friday, March 25, 2016
What's Cookin' in Those Reactors
The use of thorium in CANDU type reactors would give earthlings sufficient energy to provide for the next seven ice ages. - Edward Teller [From "CANDU Is Really Remarkable," Power Projections, May, 1980.]
Evidence in the preceding chapters strongly indicates that hormetic stimulation from low levels of radiation has great potential for improving human health and vitality. For this to come about, we must be freed from the fears promoted by the Linear No-Threshold (LNT) theory and the principles of "collective dose."
Freedom from these unreasoned fears would also promote the growth of other nuclear technology, the most important of these probably being power generation. Availability of energy can be seen to coincide with both standard of living and health. The environmental primitivists would have us live in a pristine wilderness - precisely where we see the absolute worst of the human condition. (And no McDonald's.)
Many of us would be interested in achieving greater independence from the utility companies (often government monopolies) and the government itself. We see all manner of solar toys and wind generators in Mother Earth News, which promise energy independence. Sure, as long as you have a staff of electrical and mechanical engineers, plus thousands of acres to mount the collectors or turbines, and a maintenance crew of dozens to keep things running. But as we shall see, nuclear energy has the promise to free those of us who would opt out of the government/utility networks. And while I take aim at some utilities that have become slovenly where licensure requirements have virtually eliminated competition, these same utilities would be in the best position to be the providers of community or residential power sources, having both generation and customer knowledge.
Evidence in the preceding chapters strongly indicates that hormetic stimulation from low levels of radiation has great potential for improving human health and vitality. For this to come about, we must be freed from the fears promoted by the Linear No-Threshold (LNT) theory and the principles of "collective dose."
Freedom from these unreasoned fears would also promote the growth of other nuclear technology, the most important of these probably being power generation. Availability of energy can be seen to coincide with both standard of living and health. The environmental primitivists would have us live in a pristine wilderness - precisely where we see the absolute worst of the human condition. (And no McDonald's.)
Many of us would be interested in achieving greater independence from the utility companies (often government monopolies) and the government itself. We see all manner of solar toys and wind generators in Mother Earth News, which promise energy independence. Sure, as long as you have a staff of electrical and mechanical engineers, plus thousands of acres to mount the collectors or turbines, and a maintenance crew of dozens to keep things running. But as we shall see, nuclear energy has the promise to free those of us who would opt out of the government/utility networks. And while I take aim at some utilities that have become slovenly where licensure requirements have virtually eliminated competition, these same utilities would be in the best position to be the providers of community or residential power sources, having both generation and customer knowledge.
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