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Understanding E = mc2

Posted by RBrowntn 10 years, 6 months ago to Technology
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I posted this link in another thread, but felt it might be enjoyed by a larger audience. This article has an essay by William Tucker which is the best argument for nuclear energy I've seen. It was posted in 2009, but still very relevant today.
SOURCE URL: http://www.energytribune.com/2771/understanding-e-mc2


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  • Posted by straightlinelogic 10 years, 6 months ago
    That was an informative article that will forever transform my thinking about energy, and I grew up in Los Alamos. If adapted widely enough, nuclear energy would render the whole global warming controversy moot.
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    • Posted by CircuitGuy 10 years, 6 months ago
      I have heard critics say that building nuclear plants and running them results in the same carbon emissions as burning fuel, BUT this does not ring true to me. I would be shocked if the scientific consensus agreed with these claims.

      I am confident nuclear power will be part of the solution to the problem (it's not really a controversy) of anthropogenic climate change.
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      • Posted by $ stargeezer 10 years, 6 months ago
        The carbon cost for building a nuclear power plant would exceed the equivalent coal fired plant. I'm speaking as a general contractor who has not built either, but I am somewhat familiar with the required construction techniques required for the nuclear plant and the methods used in building a coal fired plant.

        While I don't have firm figures of the dollar cost for either plant, I do know that it can take 4-6 times as much construction time to build a nuc plant. Since the timeframe is measured in years to construct a nuc plant, the carbon footprint if it's construction is much greater.

        Also while the cost of the energy produced is low compared to coal, The carbon cost for the operations of the plant, the cost of producing the nuclear fuel rods, which are replaced every year(?), cost a lot and it's all custom, one off machine work.
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        • Posted by CTYankee 10 years, 5 months ago
          Sorry, the first two generalizations slightly correct, Nukes do use more concrete than coal-burners, and they do take longer to build, those two sources of CO2 are insignificant compared to the operating differences!!! Utterly insignificant like 0.001% over 1 year, 0.0001% over ten years, and less as time goes on.
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          • Posted by $ stargeezer 10 years, 5 months ago
            The amount of energy in the reservoir of nuclear fuel is frequently expressed in terms of "full-power days," which is the number of 24-hour periods (days) a reactor is scheduled for operation at full power output for the generation of heat energy. The number of full-power days in a reactor's operating cycle (between refueling outage times) is related to the amount of fissile uranium-235 (U-235) contained in the fuel assemblies at the beginning of the cycle. A higher percentage of U-235 in the core at the beginning of a cycle will permit the reactor to be run for a greater number of full-power days.

            At the end of the operating cycle, the fuel in some of the assemblies is "spent" and is discharged and replaced with new (fresh) fuel assemblies, although in practice it is the buildup of reaction poisons in nuclear fuel that determines the lifetime of nuclear fuel in a reactor. Long before all possible fission has taken place, the buildup of long-lived neutron absorbing fission byproducts impedes the chain reaction. The fraction of the reactor's fuel core replaced during refueling is typically one-fourth for a boiling-water reactor and one-third for a pressurized-water reactor. The disposition and storage of this spent fuel is one of the most challenging aspects of the operation of a commercial nuclear power plant. This nuclear waste is highly radioactive and its toxicity presents a danger for thousands of years.[22]

            Not all reactors need to be shut down for refueling; for example, pebble bed reactors, RBMK reactors, molten salt reactors, Magnox, AGR and CANDU reactors allow fuel to be shifted through the reactor while it is running. In a CANDU reactor, this also allows individual fuel elements to be situated within the reactor core that are best suited to the amount of U-235 in the fuel element.

            The amount of energy extracted from nuclear fuel is called its burnup, which is expressed in terms of the heat energy produced per initial unit of fuel weight. Burn up is commonly expressed as megawatt days thermal per metric ton of initial heavy metal.

            http://en.wikipedia.org/wiki/Nuclear_pil...

            Don't anybody think I'm anti-nuc, I'm not. In fact I'm very pro nuc. But the issue of dealing with spent fuel materials must be addressed and dealt with. The notion that nucs are more environmentally friendly is just ridiculous. Until they are equal to coal fired in total wastes generated, I'm not saying that it's time to kill coal fired plants. And lastly, anything BO is for, I'm against.
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            • Posted by CircuitGuy 10 years, 5 months ago
              This is very interesting. I assumed that the reactors ran until the U-235 decaded; I did't know about the fission byproducts absorbing energy and making the reaction no longer self-sustaining.

              You seem extremely knowledgeable about nuclear science and not in need of making decisions based on politics. It reminds me of those boards in Fountainhead where members had to check with their political enemies and friends before taking a decision. If you are excellent at providing something other people want, i.e.estimating the cost of a power plant, you don't need to oppose/support things based on a political game.
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              • Posted by $ stargeezer 10 years, 5 months ago
                I owned a general contracting company in ElPaso TX and bid on many contracts. A very important part of my success was the ability to properly bid jobs based on relatively little information up front. Any contractor who can't look at a job and in a hour have a rough idea of the costs involved is not going to be in business long. Large jobs might take weeks to completely and accurately bid out, but the guy in charge has to look at the job first and know it's worth the couple weeks (or months) it will take to properly bid out.

                The Nuclear Science part is a side interest along with Astrophysics that's always held a particular fascination for me. My first two degrees were in mechanical and electrical engineering followed later by civil engineering. All of which opened my mind to know what is required to build about anything. Which was what we did, from bathroom stalls in a waste treatment plant to the flight simulator for the F-117 Stealth Fighter in Holloman Airbase when the wing was moved from Groom Lake to building a cabinet under a desk where a general kept his "good stuff". :)

                Of course I could have just sat back on my disability check each month and my military retirement pay and just go fishing, but that wouldn't have produced anything except increasing my waistline. Even after selling that business and retiring again, I just could not do it and continued to build a third business that also prospered until a certain government agency told me that I couldn't do what I was doing without cheating - I wasn't and after dealing with them for close to a year and half they decided that I really was the rarest of rare - a honest person that didn't lie or cheat the tax collector - at which point this honest man with tons of skills went on strike. I locked my doors, took my equipment home and sold my building for $1 less than I had invested in it.

                Yes I know a lot, but nobody except for myself will benefit from it until the present administration is gone.

                Now, I'm retired again.
                .
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                • Posted by CircuitGuy 10 years, 5 months ago
                  "at which point this honest man with tons of skills went on strike."
                  Does this mean you won't do work for money but might still act as an angel investor, funding and coaching people trying to get started? In this case you'd be doing work, not for money but to increase the chance your equity turns into something?
                  If you wouldn't do that, can you even keep your wealth invested in a portfolio of RE and stocks? Would you help a friend or relative do a repair so he/she has more money to spend on other things?

                  I know it means different things for different people, but I'm interested in the notion of people going "on strike". I find it hard to believe producers really go on strike. I imagine they're more like Dagny when she retreated to her cabin and her mind started wandering to ways she could create value in the small town near the cabin; then she told herself, "Oh stop it!" It's hard to imagine productive people being so mad about politics that they actually stop creating any and all value.
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        • Posted by Kova 10 years, 5 months ago
          So...wouldn`t these extra costs still be less than what is ultimately invested in coal? Or are you pointing out that sustaining a nuclear power plant would still be more expensive, even in the long run?
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          • Posted by $ stargeezer 10 years, 5 months ago
            I should also add that the timeframe between major rebuilds of the plants must be factored in. A nec plant cannot be partially shut down, leaving a part in operation while a partial overhaul is made like is common with coal fired plants.

            With a coal fired plant there are multiple boilers that are independently controlled and one can be shut down while others are still firing.

            In a nuc plant there is one pile and it is either hot or it's down. Whenever it's being serviced, it is totally shut down.
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            • Posted by Technocracy 10 years, 5 months ago
              Not necessarily true, depends on the plant.

              If they have more than one reactor they can always shut one down for service/refueling and leave the others up.

              There are a number of multi-reactor plants around. Makes better economic sense to do more than one reactor in my opinion considering the crap you have to go through to actually get the thing built
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              • Posted by $ stargeezer 10 years, 5 months ago
                I could be wrong, but I thought that one of the regulations that came after Three Mile Island was that they would be limited to one pile.

                Again I'm not sure of the exact regs and the exact outcome, but it seems that one issue TMI had was shared cooling systems, which is common in a coal fired plant, but it was a source of the problem at TMI.

                I'd hope we would have a more knowledgeable member jump in. As I said, I was a general contractor who sub-contracted a couple small jobs on one plant, I'm no expert, except on the small part I did (we hung the bathroom dividers, doors and did some carpentry work) which was not related to the reactor at all.
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                • Posted by Technocracy 10 years, 5 months ago
                  I am not sure if that is true or not. The sensible thing to do if TMI had an issue with shared cooling would be to only disallow shared cooling, not every multiple reactor plant regardless of cooling.

                  I don't know what the regs are, I don't work in that industry. If they did forbid multiple reactors in use even with independent cooling, that would be irrational....so likely true /rolleyes.

                  To be honest I'm not even sure they have approved a new plant since TMI. It is so difficult to get a permit for a plant of any type, its no wonder shortages occur.
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            • Posted by Robbie53024 10 years, 5 months ago
              Not necessarily. There can be multiple generators at a single plant, just like a coal or NG powerplant, so really no difference. In fact, I think that most of the Nuc plants have multiple reactors (you can tell by the multiple cooling towers).
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          • Posted by $ stargeezer 10 years, 5 months ago
            yes, providing you factor in the still existent problem of dealing with the waste byproducts of producing the fuel rods and the still radioactive "spent" fuel rods. So far there is no good method of dealing with this growing problem.
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  • Posted by robertmbeard 10 years, 6 months ago
    That was an excellent essay, written in language that should be more easily grasped by people without background knowledge in nuclear physics. There really is no comparison between currently extractable energy density from nuclear fission versus all other available energy sources. Nuclear fusion is even better, but is still projected to require 30+ years of R&D before possibly becoming commercially available.
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  • Posted by RonC 10 years, 5 months ago
    Fascinating! Quoting Joe Biden, "We are going to tax everything that moves. If it doesn't move, we are going to tax it until it does!" With that type of governance, would it be possible to ever build a project of this nature?
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  • Posted by CircuitGuy 10 years, 6 months ago
    It's great. I like how it points out that chemical reactions are not immune from this; it's just the energy released equals a tiny amt of mass.

    My wild guess for the energy of the future would be nuclear plants that inefficiently store their output in chemical bonds of some material that can be easily transported and released quickly when needed but not accidentally. The same nuclear energy could drive reactions to capture carbon from emissions we've made since the industrial revolution. Fossil fuels will be just a stepping stone in human history. I can't imagine a future without nuclear energy.

    Thanks for posting it.
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  • Posted by rstandal 10 years, 5 months ago
    Just a thought in passing, first we need to agree there is a carbon issue and second the use of thorium as a fuel solves protracted construction cost.
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  • Posted by servant74 10 years, 5 months ago
    Wonderful article. Personally I wish we would get off our toush and go the thorium route, rather than using radium. Easier to find than radium (it is almost everywhere there is dirt) and doesn't leave nuke waste that is radioactive nearly as much as radium based reactors. Also, in case of the worst happening (meltdown, no power to drive safety devices, etc) it fails safe natually.

    Check out

    http://www.csmonitor.com/Environment/Ene...

    and

    http://youtu.be/GQ9Ll5EX1jc

    and

    http://youtu.be/uK367T7h6ZY - in 5 minutes

    and there are MANY more video's on YouTube (just search for Thorium). The US Gov turned off their only Throium reactor in 1971 (if I remember the year right). They would regularly turn in on Monday morning and run it till Friday night, when they turned it off (totally safely). There is no reason our reactors couldn't use this principle. ... safe, abundant, little to no residual radioactive waste, can even consume plutonium (if we ever really want to get rid of that stuff we spent so much to refine for weapons).
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  • Posted by $ Thoritsu 10 years, 6 months ago
    This is a nice essay. Had not thought to connect the basic kinetic energy equation I've gleefully used to avoid the algebra in how high a ball will go to this epic equation. The analogy will keep me thinking, like my amateur interest interest in a relationship between energy and information.
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  • Posted by Herb7734 10 years, 5 months ago
    Atomic power is without a doubt the most efficient source of energy with the easiest to manage environmental problems that there is. If you understand the article at all, you realize that matter, when converted produces huge amounts of energy, and if we ever get fusion to work (and we will) the energy produced will be boundless. Unfortunately, the misuse of nuclear power plants can cause very creepy results because of the effect they can have on genes. As a result it becomes a "Frankenstein effect." Simple remedies on atomic power plants eliminates this and with proper application could end all of our energy problems with the unlimited power of the universe.
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  • Posted by jimjamesjames 10 years, 6 months ago
    Thank You!! Outstanding explanation. My take= away is that the energy density (one gallon?) of nuclear is equivalent to 2,000,000 gallons of gasoline.
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    • Posted by CTYankee 10 years, 5 months ago
      That's more or less correct.

      There is enough potential energy from Uranium in a cubic meter of granite to:

      1) Mine the granite out of a solid quarry face.
      2) Transport the block 1000 miles to a factory where...
      3) the stone is crushed to talcum-powder fine dust.
      4) The powder is treated with chemicals to dissolve the Uranuim.
      5) Filter the uranium salts, and boil all the water dry,
      6) remelt the dust less the uranium atoms into a new block of granite-glass
      7) transport that glass block 1000 miles back to the mine
      8) process the uranuim salts into high-grade nuclear fuel.
      9) transport the new fuel rods 1000 miles to a nuclear reactor
      10) reprocess/purify each and every atom of spent nuclear fuel,
      11) Transport the spent fuel 1000 miles back to the mine and
      12) melt a small hole in that block of granite glass and entomb the waste back in the rock or came out of.
      13) Put the block of glass back into the quarry.

      And the good news is even with all that extra effort, there is still the equivalent of several megawatt hours of energy produced by the nuclear reactor to sell to the public!
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  • Posted by iroseland 10 years, 6 months ago
    The costs for light water reactors are pretty high but a lot of the money is wasted in handling the containment problems and managing hydrogen and then also dealing with the fission products
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  • Posted by preimert1 10 years, 6 months ago
    The two Voyager spacecraft launched in the early 70's were powered by two plutonium generators each. Although we can barely hear them anymore due to free-space attenuation at such distances, There's no reason to believe that they aren't still going strong. Pu has a half-life of 24 thousand years.
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  • Posted by fivedollargold 10 years, 5 months ago
    An excellent treatise comparing energy densities of various forms of power. However, $5Au cannot agree with the author's cavalier attitude towards the risks of nuclear energy. The residents of Chernobyl and Fukajima might beg to differ with him. It would be naive to suggest that the world can maintain industrial societies without nuclear power, but one must be willing to accept the risks and work to minimize them.
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  • Posted by TheOldMan 10 years, 5 months ago
    I think that the building costs would come down with design standardization. Less custom design, more "cookie-cutter" design for most of the hard stuff. Also you can reprocess "used" nuclear fuel but I think that one of the by-products is Pu which is why the USA (Carter?) quit the effort. I think the French do it though.
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  • Posted by johnpe1 10 years, 5 months ago
    had to sleep on this one. first, kinetic energy has
    the formula E=(0.5)(m)(v squared), but our author
    wanted to maximize the visual similarity and fudged it.

    second, we can chemically separate the "waste"
    products from "standard" reactors, though it isn't
    easy. if we keep on with this anti-fossil-fuel bent,
    it will become profitable at some point. we had
    a posting here in the gulch about re-use of spent rods.

    third, we have this article "prettied up" in word
    if anyone wants it -- principle subbed for principal, etc.

    and the speed of light is 2.998 times 10 to the eighth,
    and when squared is 8.99 times 10 to the 16th,
    or 89.9 quadrillion, just for effect. BIG. if we
    homo saps had any sense, we'd watch the red
    chinese do molten salt, and make 'em like doritos!!! -- j

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