Why do people fear nuclear power?

Discussion in 'Science & Society' started by Stokes Pennwalt, Feb 5, 2004.

  1. Stokes Pennwalt Nuke them from orbit. Registered Senior Member

    Just in case anybody is curious about my sources, I spent twelve years in the Navy as a surface warfare officer on nuclear powered ships. Additionally, I've assembled a synopsis of the events which took place at Chernobyl, just to dispel any rumors of the potential for a repeat in the west.

    This is very long, and I've broken it into three posts. I'll caution you that this is not the complete story, and I've simplified some very complex interactions. Just take it for what it's worth. Anyway, here we go:

    You wouldn't use a toothbrush to unstop a toilet, would you? Sure, with some effort you can probably make it happen, but that doesn't mean there's any wisdom to it. In pursuit of this your friends would be quite justified in saying "what the fuck are you doing? Oh never mind. I'll just go get you some hemlock." Strangers couldn't be berated for making the same observation. Even more alarming would be watching you put the toothbrush back in its holder by the sink after an admittedly hard-fought success. Much the same is true about Chernobyl, only in this case the Soviets were trying to brush their teeth with a plunger. It's no surprise that they wound up eating a lot of shit.

    Chernobyl was a quagmire from the start. The reactor, called an RBMK type reactor, was designed as a quasi-breeder to add some measure of plutonium production in order to supplement the Soviet weapons program. This called for a lot of design elements that would have otherwise not been necessary. Chief among these elements was reliance on a fixed graphite moderator.

    And now for some reactor theory

    The moderator does a couple of things for a reactor, but mostly it acts as a speed brake for neutrons. Most neutrons produced in a reactor are traveling too fast to interact with another fissionable nucleus. They’re called “thermal” neutrons because they’re hotter than usual, and on this scale being fast, hotter, and heavier all mean the same thing: more energy. To reclaim these neutrons they need to be slowed down, or thermalized, so that they can cause more fission. In a weapon, the rest of the plutonium or uranium does this naturally because its cross section for collision is very high and the reaction mass is set up for it geometrically. This is not the case in a reactor; they’re laid out to prevent the fuel from thermalizing the neutrons. If they weren’t, the reaction would essentially be in a steady-state critical reaction and controlling it would be very difficult. Instead, the process of slowing the neutrons is left to a moderator. In a reactor, if the moderator were to stop working, the reaction will stop in just a few hundred fission generations since the neutrons being produced are too high energy to interact with the fuel rod arrangement. You can read more about fast neutron moderation here

    The RBMK design at Chernobyl had a graphite moderator built into the core. There are tubes or shafts of graphite surrounding the fuel rods to moderate the reactor. As with any reactor, careful moderator engineering allows you to control a large number of variables, not the least of which are fuel density, response times, and a bunch of natural circulation properties. RBMK's are a quasi-breeder design that runs off 2.4% enriched uranium and breeds a small amount of plutonium-239. It's not a full breeder like the liquid metal fast breeders, but it still does carry on a small amount of the fast-neutron plutonium reactions. This necessitated that the moderator must return some higher energy neutrons to the fuel, but moderate most of the others. Without getting way too far into how that one works, just take it on faith that graphite moderation was the best option to be breeding plutonium in the RBMK.

    The graphite moderator gives RBMKs what's called a "positive void coefficient." This means that any air pockets in the cooling water causes an increase in the reaction rate. When the water around the fuel rod is displaced, neutrons are allowed to flow more freely into the moderator (this has to do with some of the neutron absorbing qualities of water), and with a permanent graphite moderator wrapping the fuel rods, there's nothing to buffer the reaction and it continues to grow. Additionally, the fast neutron reaction necessary for the breeder qualities would interject a wide range of neutrons energies that, without the water to absorb them, would be moderated back into the fuel and accelerate the reaction. And more so, when operating at very low power levels the neutron-producing spontaneous fission of the relatively high levels of plutonium in the core can unexpectedly start fission cycles that are many hundreds of generations long, and the presence of a void space can cause dramatic and uncontrollable power spikes.

    Another peculiarity of reactors that contributed significantly to the disaster is what's called xenon poisoning or xenon smothering. A common by product of U-235 fission is Iodine-135. This iodine, of its own right, is relatively unremarkable, and has a rather short half-life of 6.7 hours, decaying into Xenon-135. Xe-135 is extraordinarily good at absorbing Neutrons; in a reactor it has a cross section of neutron absorption almost a million times that of Uranium. As a result, the presence of a small amount of Xe-135 can smother a reaction by depressing the neutron flux (the Xenon is absorbing the neutrons rather than the Uranium). Once Xe-135 absorbs its neutron it becomes Xe-136 and its cross-section of absorption becomes very much smaller and its interaction with neutrons is no longer of consequence.

    Xe-135 levels are usually managed by an equilibrium of the reaction rate. At any given power setting Xe-135 is going to be produced at certain rate. Reactor designers are well aware of this, and simply allow enough excess neutrons to be produced that they can be lost to the Xenon without a significant performance impact. But the Xenon smothering becomes very important when changing power settings.

    Imagine that you had run a reactor at 100% power for several days. The Xenon levels would have long ago established an equilibrium and would have been fairly constant, and every thing is happy. Now say you command a power decrease to 50% power. You drop your control rods in to absorb some neutrons until you get down to 50% in a few minutes. Thinking that everything is happy again, you go on about you business. The next day you notice that the power level has risen to 65% with out having ordered any changes. This is because at the time you started the power decrease the core was saturated with Xenon, and as you lowered the rods the xenon was still being produced at the 100% power level. Remember that the Xenon is a decay product of Iodine, and it takes several hours for Iodine to decay. In the few minutes it took you dropped your rods in, and for the several hours late, the Xenon production was as if the reactor was still at 100%. About 10 hours later the Xenon production level will fall as the Iodine finishes decaying, and it'll take about 40 to 50 hours for it to fully settle out at the new level. Xenon has the effect of masking the real power setting of the reactor until the equilibrium is restored. It acts as a temporary absorber of neutrons, and once any excess is consumed, the power level will change. This becomes critical to events at Chernobyl when considering an ordered increase in power. In the mean time you can bore yourself to tears with Xenon transients here.
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  3. Stokes Pennwalt Nuke them from orbit. Registered Senior Member

    Monty Python Presents: Chernobyl

    The accident at Chernobyl happened while the plant was conducting a test to see how long the turbines would roll after a loss of power. In preparation for the test, on the afternoon of April 25th, the emergency core cooling system was disabled. The test was supposed to be done that evening, but the supervisor for the Kiev power grid requested that it be delayed until later that night. Around midnight where was a shift change, about an hour after they got permission to continue with the test. Because of the positive void coefficient, the minimum allowed core power, according to procedure, was 700 megawatts. By 12:30am on the 26th the operators had already lowered the power to around 500 megawatts. The operators then failed to set the system to maintain ordered power levels, and the power continued to rapidly fall to around 30 megawatts.

    In an effort to get power levels back up, the operators began removing the 211 or so control rods from the core. Again because of the positive void coefficient, 26 control rods were supposed to remain in the core at all times. In the event of a loss of water the control rods would absorb excess neutrons and keep the reaction under control until water could be restored. When the operators removed the rods they saw only a slight rise in power and continued to remove more rods. To raise the power the operators removed all but 9 of the control rods before it stabilized at 200 megawatts.

    The core, at this point, was deep within a xenon transient form the long run at a full power setting in the previous days followed by the very lower power settings in the previous hours. The rods were fully retracted and the Xenon was keeping the reaction rate down. As the Xenon continued to absorb neutrons, the smothering effect diminished and the reaction rate grew. The operators saw the small initial increase and tried to keep their 200 megawatt level by lowering some of the rods back in. Rapid boiling followed as the reaction started to becomes uncontrollable, and the graphite moderator continued to accelerate the reaction. A critical threshold was crossed and the reaction rate started to grow exponentially as the xenon was consumed. In somewhere less than a second the power level spiked to over 7 terawatts, instantly flashing all the water into steam. As the reaction rate continued to increase the steam reacted with the Zircon cladding and produced a huge amount of hydrogen and oxygen gas.

    Two explosions followed. The first was as the fuel channels and steam piping were blasted open from steam pressure, followed abruptly by the 26 ton concrete biological shield atop of the reactor vessel being blasted through three stories of the complex above it. The shield flipped upside down and landed back in the core itself, fragmenting most the fuel that hadn't already melted and leaked out the bottom of the ruptured tank. The sudden rush of oxygen into the containment vessel, combined with the extreme heat, started a fast and hot burning graphite fire that spilled out, over the next two days, more than 100 million curies of radioactive debris.

    There are a couple of things unique to Chernobyl. First and foremost is little if any knew knowledge was gained from these events. Every single performance characteristic that the reactor went through from the time they started the low power run until the time of the explosion was a known, predicted behavior. The xenon smothering was no mystery. The lower-power spike was no mystery. The positive void coefficient was no mystery. That they were operating the reactor in a very dangerous condition was known full well by the operators, before they even started the test. Built into the system were more than 30 safety interlocks to prevent them from doing exactly what they were attempting. And they physically disabled each of them. So let me summarize the acts of premeditated stupidity of the operators like this:
    • The operators deliberately disabled safety equipment that was designed for no purpose other than to prevent an uncontrolled core situation.
    • The operators deliberately aggravated the reactor by causing the lower power situation.
    • The operators failed to activate the emergency core cooling when they entered the low power situation (this would have prevented void formation).
    • The operators failed to recognize the xenon smothering, and removed more rods.
    • The operators failed.
    • The operators were licking operational urinal cakes to freshen their breath prior sucking the peanuts out of their own asses while reenacting Caligula's "Garden of Chocolate" escapade.
    • We shall rejoice that most of them died in the accident, as these people had long ago exhausted their usefulness.

    That being said, the critical design element was the graphite moderator causing the positive void coefficient. This specifically makes the reactor unstable in any condition other than fully operating. Any event, such a major coolant leak, would have caused a disaster. The RBMK design is only tacitly stable, and even then only when operated properly. People who understood reactor design in that day and age were not surprised by the Chernobyl explosion. I said earlier that the soviets were trying to brush their teeth with a plunger. I have a hard time imagining this reactor design accomplishing much else. Despite the claims, this thing wasn't design to be a power reactor. It was a very cheap breeder that did power production on the side.
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  5. Stokes Pennwalt Nuke them from orbit. Registered Senior Member

    Light Water's warming glowing warming glow.

    So Chernobyl was caused by a collision of operational autism and design failures. Luckily, very few reactors are susceptible to power spikes like the RBMKs are. In the west the predominant design is called a Pressurized Water Reactor (PWR) and it's somewhat less popular cousin the Boiling Water Reactor (BWR). Both of these make up a family called the light-water reactors that are by far the dominant design used in the west. Of 441 power reactors are currently operating world wide, 351 are PWR/BWR types, more numerous than all other reactor types combined.

    The principal feature of a PWR/BWR is its reliance of several redundant passive safety mechanisms. Of these features, the biggest and most easily recognizable is that the light-water family of reactors are water moderated. The reaction and fuel density is balanced such that water flowing through channels between the fuel rods is sufficient to moderate the reaction at controllable levels. The water also acts as reflector for very low energy neutrons (ones that don't need moderated) and returns them to the fuel before they are lost to the reaction. Lastly, the water absorbs neutrons in certain energy ranges; this helps keep a upper limit on the energy of the neutrons being returned to the fuel. Most of this is made possible by using 2.5% to 3.5% enriched fuel that has a high enough occurrence of natural spontaneous fission that the neutron flux in the presence of water is sufficient to allow the reaction to continue.

    I just finished a rather lengthy explanation of how the graphite moderator in the RBMK led to the low-power instability that caused the accident. Now consider the implications of this: the water is performing two functions that are critical for the reaction to continue: moderation and reflection. Lose either and the reaction stops (fuel configuration alone will not allow it to continue). This leads to a "negative void coefficient" meaning that any bubbles in the water slow the reaction down. In the event that all the water flashes to steam, the reaction stops. Even if all the water were to leak out, the reaction would still stop. These qualities all but eliminate the possibility of dramatic power transients seen in other designs. PWRs/BWRs are relatively slow to respond to changes and telegraph their condition quite well. There are very few scenarios that lead to disaster in the core because nearly all scenarios are contingent on run-away reaction rates that would flash the water to steam, halting the reaction.

    Some of the worst case scenarios include a loss of coolant flow to the core. In this situation the reaction is still continuing because water is present, but it will continue to be heated by the reaction until it eventually boils into steam. As the water boils the core will becomes partially exposed. The submerged portions will still be moderated and producing heat, but the exposed portions will be surrounded by superheated steam (a very poor coolant) and already be very warm on its own. In this situation severe core damage is possible due to extreme heating, as in the case of Three Mile Island, but the design is such that the water will boil off and stop the reaction before the core can fully melt. If somehow the partially submerged core receiving water at a rate approximately equal to the boiling rate, and the partial exposure were to remain somewhat constant, then the exposed core could possibly melt. There are, however, fail-safe gravity flooding systems to interject water saturated with boron or cadmium into the core. The water would cool the core, and the boron and cadmium would absorb neutrons that would have otherwise been moderated back into the fuel. This would effectively stop the reaction in a very short time period.

    Overall, the most plausible failure of a PWR/BWR plant is that of a loss of containment. This would involve the primary coolant somehow escaping from the reactor building to the outside environment. There are number of ways for this to happen, but overall minor leaks are just that: minor and ignorable. It would take tens of thousands of gallons of coolant escaping all at once to have a significant impact. However, it should be pointed out that this is a risk with any reactor, and the PWR/BWR design is such that the coolant is readily contained and controllable, and the risk is significantly less than with some others (such as the various gas cooled designs, and the liquid metal reactors).
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  7. Fraggle Rocker Staff Member

    Excuse me but since I'm not a nuclear physicist like some of you, I've been watching this thread patiently, waiting for an answer to my question. So far it hasn't appeared.

    What about that waste disposal?

    One of you pointed out that fusion reactors produce far less radioactive waste than fission reactors, but the figure you gave for volume per year is still a whole lotta radioactive stuff that has to be put somewhere and kept safe for... let's see...

    Well, as I said I'm not a nuclear physicist, but I've seen the answer expressed in years and it had a lot of zeros.

    The fear arises because the oldest continuous civilization on this particular planet is China, at five or six thousand years. Human civilization in aggregate, treated for the sake of argument as a continuous institution, which it most definitely is not, goes back barely ten thousand years, if that.

    Where and how do we hide a blob of deadly radioactive material that large (or a large bunch of smaller blobs if that proves easier), with enough shielding, enough warning labels, and enough idiot-proofing, to make sure that twenty thousand or a hundred thousand years from now, our distant descendants will still know what it is and/or be unable to open it by accident and wipe out the population of the surrounding area?

    The ways this could happen fall into a couple of categories.

    Civilization could be destroyed by a cataclysm of nature. A plague worse than AIDS or bubonic. Giant asteroid. Ice age or global warming scenario more extreme than anything we've found in the core sample records. (Pick your cause: solar energy variation, big muthah volcano, etc.) Some other cause we haven't thought of...

    Civilization could be destroyed by human folly, the "Dark Angel" scenario only worse and planet-wide. Nuclear, bio, or chemical warfare or terrorism. Putting too much faith in computer software engineered to the quality standards of the Bronze Age. Civil and governmental leadership even more incompetent and short-sighted than what we have now.

    In either case once civilization falls, written language could easily disappear. Small, nomadic tribes have little use for it and the last literate priest will eventually die. Even if one layer of civilization dies to be eventually replaced by another, the written records of the earlier one may prove indecipherable. The Romans could not read the Etruscans' language even though the gap between their civilizations was pretty short. Even we with our sophisticated multiprocessing computers can't figure it out. If the Etruscans had buried a nuclear waste dump and covered it with warning signs, two thousand years of archeological snooping would have eventually found it, jimmied it open, and turned Italy the wrong shade of green.

    Even if you put a lot of faith in oral legends, how many generations can retell one before it morphs beyond recognition? Especially if the subject is one that the receiving generation has no context to facilitate understanding. Our own children know the dangers of playing in the street or in a discarded refrigerator yet these activities still kill a number of them. How many adult Scythians would have heeded a warning about a strange stone box that makes you die a hideous, ugly death if you get too close to it?

    Is the half-life of fusion waste really so short that we don't need to worry about warning people who will be alive thousands of years from now? Especially if a couple of thousand years of fusion powered civilization discard a couple of thousand of those gigantic hazmat cartridges that one of you described, neatly labeled in our words and Smilies.
  8. Mr. Chips Banned Banned

    Stokes Pennwalt: "I'm not inclined to begin unless you can promise to spare us from a page-long, confusing, and inarticulate diatribe."

    Yeah right. I have reason to believe that you speak with forked tongue white man. Appears that quantity is more important to you than quality, basically "might makes right." Well, all those words you threw here just plain old puts you in the light as someone who really doesn't care for truth or communication. I really do not think you are willing to communicate as there is no way I or any sane person would want to wade through the mounds of garbage you posted, SP, ole buddy, ole pal. You seem to be quite a sorry bloke.

    So, to get back to my train of thought, this LNT is interesting. If you look around you see that the history of NRC's and IAEA's adoption and current holding of this theory of Linear No Threshold is full of past and continuing controversy even according to posts on their own web sites. They agree that no threshold exists, that is any amount causes damage to life, and then they go about stipulating some "thresholds" of safety. In order to allow business to go on they can only play lip service to the LNT hypothesis.

    Take a look at the safe dosage restrictions (which appear to have been generally and regularly decreasing with time). The IAEA does a better job than the NRC as far as placing these in a readily accessible site on their web presence and attempting to explain the different dosages. When you finally do locate the NRC's safety regulations looks like you're going to need an NRC cohort present every time you want to try to apply them in order to translate. It is basically a mess and not readily discernible especially when you go about trying to figure out what a rem is and run into this concept of RBE or Relative Biological Effectiveness. Wee, isn't it nice to know that now we need a physicist working in conjunction with a biologist to determine whether or not it is safe to handle that 50 gallon drum of radioactive waste or even to push a broom down the corridor of a plant. Add to that the number of different exposure limits for different categories of people by age and then by worker verses general public. Why in hell are workers allowed higher exposure than the general public? I can't see the reasoning behind this except that maybe it is necessary if the work is to be done at all. Are the safe dosages for a worker so much higher than the general public because they are not human? Of course not, it is obviously for expediency, in other words, what is safe is determined by the economic advantage to be had.

    Which reminds me of something. Nasor, money requires engineered scarcity in order for it to continue to have value. Think about that. If everybody had plenty of money who would do the work? Dollars and cents do not determine safety or feasibility. Use and continued respect for money is support for an elite that can afford to use people as sacrifical chattel. This relates directly as to why safe nuclear energy (solar) appears economically impractical while the dangerous, more centrally controlled (read concentrated profits) methods appear more feasible, why something with no threshold of safety can be used. Some frequency of deaths is acceptable in such a scenario. Eventually humanity is going to have to learn to distinguish between cents and sense.

    Which brings me to Fraggle's astute observations. Human social experiments have generally decreased in longevity virtually geometrically over the ages and the transition between one and the next is often violent. How on earth can we expect the monitoring and keeping of deadly long lived toxins safe from release into the environment when these systems that now hold the responsibility seem to be incapable of lasting more than a couple of hundred years?

    I am forced to conclude something. Those who consider nuclear power as safe have got a few screws loose somewhere. This does meet some other information I have been researching that demostrates some strong reason to believe that the normal human psychological profile is quite disturbed. I tell you, to become long lived individuals and members of a long lived species is a tricky and challenging task. Good luck all!
  9. DarkMadMax Registered Senior Member

    Mr.Chips and Mr .Fraglles replies only shows that most protesters are ignorant morons driven by public opinion/press/their own inferiority complexes.

    You shouldn't protest about something without
    understanding the basics.

    "Lot of zeroes" and "whole lotta" is exactly how much? How about coal plants which produce much more than "whole lotta" in radioactive exhaust (straight into air btw) in addition to general air pollution and co2 atmosphere contamination?

    And thats exactly how? You seem to attribute some magical qualities to reactor waste besides simple radioactivity. It should self-spread somehow to cover italy? And its also "wrong shade of green" - bohoo looks more like another mystification ("green goo").

    Chernoble was almost deliberatley produced ( by incompetent staff on compromised design with dangerous test) - humans can screw many things if they want, you can drive plane in highscraper or use it as a mean of transportation . Should we ban airplanes now too?
  10. Mr. Chips Banned Banned

    Hey DarkMadMax, if you are going to call me names could you please cite the data that causes you to leave your cognitive abilities behind? Did you forget that you had accused more than one person? Let's see if you can do some damage control here. Somebody is definitely looking at least somewhat moronic.

    BTW, why don't you not address the important point of Fraggle, the unassured longevity of human social systems within the time frame of needed monitoring for the radioactive wastes. That convenient omission of yours helps you look quite (maybe moronic is the wrong term as that is rarely applicable to humans and only resorted to by such as yourself) dysfunctional. It is as if you are defending a heartfelt belief rather than an evidence driven opinion.
  11. DarkMadMax Registered Senior Member


    High level nuclear waste consists of spent nuclear fuel, reprocessed materials, and transuranic materials (heavier than natural isotopes of Uranium, ie Plutonium). The spent fuel rods contain about 94% irradiated Uranium, 1% plutonium isotopes and 5% various other isotopes. High level waste is unique due to a very long half life and a high emission of radiation. Canada produces about 20 cubic metres of high level radioactive waste each year. All the spent fuel from Canadian nuclear reactors that had accumulated by the end of 1990 would fill one olympic sized swimming pool. "

    the rest can be found Here

    Where is your evidence ? Seems " you are defending a heartfelt belief rather than an evidence driven opinion."

    I frankly don't give a shit what happens in 5k years and if a few members of primitive civilization might be hurt if they conduct archeological excavations on mount yucca . What matters is that in big picture is taht current energy producing technologies (especially oil/coal based ) do incomparably more harm to environment than even antiquated nuclear reactors .
  12. Stokes Pennwalt Nuke them from orbit. Registered Senior Member

    If we weren't encumbered by Jimmy "hurr Plutonium sux" Carter's retarded breeder ban, we would be able to reprocess spent Uranium fuel while recouping even more energy from it.

    But there is more to it than that, so let me answer your question in greated detail.

    It may sound fanciful to say we'll throw it into space, but someday, that is exactly what we will be doing. In the interim the best option available is to concentrate spent fuels (after reprocessing, which is currently banned in the US) in a repository. This is precisely what Yucca Mountain is going to achieve. Bear in mind that 75% of the decay process takes only 60 years, as both I-131 and Sr-90s half-lives are approximately 30 years.

    Burying spent fuels for long periods of time may not seem like a very elegant solution, and if it doesn't, I'm inclined to agree. However, a few hundred tons of concentrated waste buried deep within a mountain is immeasurably preferable to hundreds of thousands of tons of ejecta released into the atmosphere, scattered hither and thither by the four winds.

    Incidentally, coal combustion actually releases more Uranium into the atmosphere than all the nuclear plants and nuclear weapons facilities and tests ever conducted.

    It's the least odious of many evils, for the time being, and the most effective stopgap between organic fuels and the holy grail of sustained fusion.
  13. Mr. Chips Banned Banned

    Ah, Stokes, nice of you to stop with the preaching thing. You and DarkMadMax, who said we should go for the fossil fuels? I am not an admirer of coal burning. Whether it be fossil fuels from this sun or the even more distantly removed remnants of stars that went nova quite some time ago (your version of nuclear energy) I prefer we get closer to the source rather than messing with all that super dead stuff. I guess you two confused my recognizing that they are nuclear derived with the idea that we should depend on them to ever greater extent. If I said such a thing point it out to me. I like to see my mistakes as I am attempting to learn how to be a better human. Oh well, there's no accounting for you "eco-nazis" and your ability to hold down an informed conversation as Stokes invoked.

    DarkMadMax, do you remember Winston Smith, the main character in George Orwell's book, 1984? Did you ever read that one? Remember how his rebellious truth loving spirit was broken? Well, with this little brief comic interlude you brought here I flashed on what Orwell was trying to teach and it is pretty easy to see that the lesson he had to share was quite valid. The characteristics of the broken person are that they really don't care for any one else except for themself to the exclusion of reason or sanity. War is peace, love is hate, are just fine as long as the self is not hurt and gets rewarded (like a trained Pavlovian dog). People have had their altruism stripped from them due to stress, torture or what have you. If life is removed from them by time or space, it is not of their concern. One can not help but feel some pity but I, for one, will hope and strive to avoid that burn out, that loss of love for life for as long as I can and maybe, just maybe, I can hold out long enough. Sorry to hear of your misfortune.
  14. Vortexx Skull & Bones Spokesman Registered Senior Member

    I would feel much better about nuclear fission once they get serious with minor actinide burning reacors to squeeze the last drops of energy out of the nuclear waste and transmutate it into something less dangerous.

    The most dangerous in nuclear fission is not the technology but the human factor, you can upgrade the technology, but it is harder to upgrade the humans to make less misstakes or invest enough money into backup safety and maintenance (like we had seen with the russians), but I think that the designs for Pebble reactors offer the potential to withstand humans operating it on a bad hairday.
    Last edited: Feb 9, 2004
  15. Stokes Pennwalt Nuke them from orbit. Registered Senior Member

    PBMRs will happen. Currently there are no PBMR plants licensed for construction by the NRC or DOE, though. This will change.

    As far as reactor technology goes right now, Westinghouse has just finished development of the ABR600 and ABR1000 plants (600MWe and 1000MWe respectively) and they have already received approval from the NRC. General Electric has also developed the ABWR.

    All three of these designs exhibit revolutionary improvements over existing PWR/BWR plants. One thing to take note of is the resurgence of BWR plants in recent years, both in the US and abroad. First, a bit about PWR designs.

    A PWR system uses a steam generator to exchange heat from core coolant to the turbine loop. For many years they were preferable for two reasons:
    • A PWR does not allow core coolant to boil because it is under such intense pressure. This increase in neutron cross-section means that fuel elements don't need to be as heavily enriched with U235, because the liquid slows down thermal neutrons to the point where the atoms in the fuel are able to absorb them.
    • PWRs isolate the radioactive core coolant from the turbines through the use of a steam generator and pressurizer loop.

    BWR designs, on the other hand, tend to be more efficient at power production becaue it's a single loop to the turbines, and therefore no additional heat loss in the steam generator. Given the state of turbine technology, especially having overcome some daunting blade erosion issues in recent decades, they're becoming more and more appealing. One drawback is that fuel for BWRs needs to have something on the order of an additional .5% of U235 content in order to capture neutrons, since steam and water vapor isn't as efficient of a speed brake for neutrons. This is more of an issue abroad though. The US Uranium enrichment industry was originally built mainly an offshoot (and sometimes part of) the early nuclear weapons programs post-WWII. As such, American Uranium tends to be enriched with a higher content of U235 anyway.

    This is also the reason why Europe prefers heavy water reactors. Deuterium water slows neutrons a hell of a lot better than light water does, so the fuel rods don't need to have as high a content of U235 to be neutron captive. They spend their time making heavy water, we spend ours enriching Uranium a little bit more (about 2% more U235 than European fuels). The end result is the same, however, and neither method is "better" than the other.

    Incidentally, you can read the NRC's final report on Yucca Mountain here. Also, President Bush's Nuclear Power 2010 program, which is intended to revamp the US nuclear power industry, can be looked at here. I recently wrote an essay summarizing it, and I can post it, if anybody is interested.
  16. Mr. Chips Banned Banned

    Westinghouse and General Electric, ah, stalwart promoters of safe and sound engineering plans, also chief owners of US based media, CBS and NBC, Suppose they would never instigate news slants for profit protection, hey?

    General Electric incidentally is cited as the thirteenth largest donor to the Bush campaign treasury at http://progressiveliving.org/mass_media_and_politics.htm
    The following is from http://www.endgame.org/dtc/g.html

    "GE made it onto the Council on Economic Priorities' short list for worst environmental offenders, for its operation of the Hanford Nuclear Reservation in Washington State; its dumping of PCBs into the Hudson River in New York over 30 years; and its deficient nuclear containment vessels"

    Westinghouse certainly seems to be quite the saintly protector of public safety, right? Here's a little story of how they tried to disarm a whistle blower who reported their safety transgressions:


    For more on Westinghouse and their environmental track record just try putting "westinghouse ********" into Google. Heck, I discovered one of their great enterprises resulted in a superfund clean up site right here in the city where I live.

    We can trust Bush's environmental policies to hold public safety as top priority NOT! http://earthhopenetwork.net/bush_watch-my-war-hand_not-my-domestic-policy-hand.htm

    Stokes, just ignore the protestors. They have no data to back up their claims of suspicion. They are just morons or nazis or ill-informed, right? You know who can be trusted. You know what is safe and not. You are god.
  17. Mr. Chips Banned Banned

    I find that this thread has helped me grasp more the reasons why some are afraid of the safe use of nuclear power. I do believe it is an ego thing, not the fault of any one but rather the repercussion of circumstances. Human society has yet to learn of the value of ergodicity so alienation and isolation are still allowed free play leading to people who do not see themselves as connected or part of humanity. People see themselves as rather purposeless disjointed entities seperate from the biosphere or even a shared universe in the ways that are our collective human nature. To them life is a case of good guys verses bad guys, disconnected processes with no necessary cause and effect and with no ultimate purposes or moral imperative except personal feelings. Using a strict definition of terms, what I believe I am whitnessing here is the megolomania of existentialism.

    Since good and bad are relative concepts these paranoid individuals are reduced to seeking a big power (big brother?) to protect them from what they generally see as an extremely frightening universe. The corporations, especially with ties or implicit military functions, becomes their god or gods, behind which the paranoid attempt to hide. They are reduced to seek allegiance to power factions that can defend their finding that evil or unacceptable behavior is the fault of the people exhibiting the distasteful opinions and not of any relation to the quality of the information they may have. In other words, science has no place in their reasoning.

    The way this thread was started is exemplary, being a general critique of the nature of any one who would not believe in the author's point of view. This is not science and we can see that the staunch adherence to this idea that we still don't know how to use sustained fusion, a totally false entirely unscientific point of view is religiously repeated. The man is afraid of science.

    Take it easy. Take a few breaths. We have here the most fantastic planet we've ever known and probably will ever know. These incredibly beautiful and complex living webs support our ability to share with each other, to revel in wonder and reverence at this rare and precious gem called life.

    I don't think there is any getting through to most of these sociopathic individuals with just communication alone. What will be the deciding factor in humanity's fate will be whether or not we can see the danger of allowing ivory tower tyrants or slum lords decide our policies from their fear and love of violence, whether or not we can find a viable way to socialize that allows us to embrace science rather than shun it.

    People fear nuclear power because our society lacks the controls and balances that allow people to feel secure. Science is sacrificed for the false security of aligning with power and this leads to more accidents, more reason for more fear. As long as people deny their own fear, the situation will just continue as it has, to ever greater accidents of ever greater magnitude as the true believers, the servants of the monsters of our times, will sacrifice their little known humanity for the fleeting and false security of the boss tyrant.
  18. Stokes Pennwalt Nuke them from orbit. Registered Senior Member

    Thanks for the endorsement.

    I only ignore protesters who are uninformed. Sadly, that tends to be a huge majority of them. That's the entire premise of this thread (which a lot of your posts actually reinforce).

    As far as your posts go, they seem to consist solely of political red herrings, like Westinghouse donating to the Bush administration. You know as well as I do that that has nothing to do with the technology.

    You will notice that I addressed others' posts about safety, waste disposal, and other engineering issues in detail.
  19. Mr. Chips Banned Banned

    That was General Electric I referred to in that way. I think the track record of these institutions you would claim as trustworthy are a major thing that can be looked at as to how far their development of technology can be trusted but ignore that if it doesn't fit your love of them and try to say my main points are red herrings. "Fool me once, shame on you, fool me twice, wont get fooled again," (LOL) remember Bush's inability to speak the self-critical part of that statement?

    I realize that you can not face the claim that your basic premise is totally anti-scientific so you have to pat yourself on the back for your ability to get lost in details. Continue to have the high opinion of yourself if you wish. I do believe in time, as responsibility will come to the forefront of human governance, you will find your freedoms curtailed in direct relation to your megalomania.
  20. Stokes Pennwalt Nuke them from orbit. Registered Senior Member

    What thread are you reading? Jesus.
  21. Mr. Chips Banned Banned

    Cognitive dissonance has got you bad, getting your facts wrong not only in a grand general way but even when referring to data in another post in the same thread from the same web page. Rather than being able to admit your mistakes you have to go about and accuse me of "confusing, irrelevant, rant."

    Another fine mess of a human brought to us courtesy the US military.
  22. RonVolk Registered Senior Member

    I think people are scared of nuclear power because they don't understand it, and there's the "Not in my Backyard" attitude. I look at it like this: Nuclear power plants posible melt down, but with a trained, competent, staff following saftey procedures the risk is probably minimal we'll get left over crap were going to have to get rid of somewhere though. Fossil fuel plants, we'll eventually exaust are fossil fuels, but we'll poison the enviroment before we run out. Benefits of fossil fuels? Big companies mine fossil fuels and they like making big money by selling electricity. Didn't something real big happen recently in world events thats related to a fossil fuel? Till we can make a cheaper "greener" form of energy I'd go with Nuclear power.
    Honestly, its not worth arguing about, if public opinnion started to look down on fossil fuel plants and public opinnion wanted nuclear energy, the high rollers of the fossil fuel selling corporations would demonize nuclear energy so fast you wouldn't be able to say "Chernobyl."
  23. river-wind Valued Senior Member

    a few items.
    1)Plants, IIRC, are about 40% efficient in converting light energy to a usable form. Now that the structure of the photosyntheic molecules have been seen, we may be able to more easily produce higher-output photo cells.
    2)wind power is a great thing, but often creates a fair amount of noise polution. possible options of setting up system out in the ocean are being tested.
    3)SNAP units. I was once told about a thing called a SNAP unit by a guy who used to work w/ the gov't. sealed steel ball, tablespoon of radioactive material, thermonuclear couplings. He said that it was invented in the 50's, but the patent was purchased by a conglomerate of the major oil companies of the time, with the stipulation that the Navy and NASA could use the units in powering their nuclear ships.
    He mentioned that one unit, relativly unmaintained, could theoretically power a city block for a few years.
    I'd be interested on your comments on the matter, Stokes.


    edit: oh, I forgot. where does the nuclear waste go?
    Yucca Mountain
    Last edited: Feb 13, 2004

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