virgin-burner 1 #26 November 3, 2009 Quote Quote nuclear power pays my bills and funds my skydiving addiction! Do you work with Homer Simpson? how do you know!? “Some may never live, but the crazy never die.” -Hunter S. Thompson "No. Try not. Do... or do not. There is no try." -Yoda Quote Share this post Link to post Share on other sites
Rstanley0312 0 #27 November 3, 2009 QuoteThat is a good question. Spent fuel waste isn't really generated very often from a reactor. Once a reactor is fueled, the uranium stays in for a very very long time. An even more interesting question is why do people think of spent fuel when they think of "nuclear waste"? The overwhelming majority of "nuclear waste" is clean enough to eat off of. As a rough estimate from experience, I would say that far less than 10% of volume disposed of as "nuclear waste" actually has any real or significant contamination. You would be shocked to see the amount of day to day things that get disposed of as "nuclear waste" at a nuke plant, yet you can dispose of your smoke detectors in the trash and have them around your house. The poly bags just keep piling up. What about Thorium? http://www.technologyreview.com/Energy/19758/?a=f is it really cleaner? Less waste?Life is all about ass....either you're kicking it, kissing it, working it off, or trying to get a piece of it. Muff Brother #4382 Dudeist Skydiver #000 www.fundraiseadventure.com Quote Share this post Link to post Share on other sites
billvon 2,454 #28 November 3, 2009 >What about Thorium? Not a bad technology, but not a lot of significant advantages over a uranium LWR. You still need "seed" material (U233) to start the reaction and you still have the spent fuel to dispose of. It's interesting to some because thorium is _very_ plentiful. Quote Share this post Link to post Share on other sites
billvon 2,454 #29 November 3, 2009 >Is it true that one of the reasons we have so much high-level waste >material is because it isn't allowed to be reprccessed into fuel here in the >US? Partly, yes. >I have heard that the "Uranium Industry" got the reprocessing banned >"way back when" to keep demand for their materials up, without worrying >about what to do with the used fuel. It's mainly a proliferation issue. If you can reprocess fuel, you have a source for weapons-grade plutonium and uranium. That's a _very_ dangerous capability to have, so it's often a political decision to not develop the capability for the sake of security. Quote Share this post Link to post Share on other sites
Rstanley0312 0 #30 November 3, 2009 Quote>What about Thorium? Not a bad technology, but not a lot of significant advantages over a uranium LWR. You still need "seed" material (U233) to start the reaction and you still have the spent fuel to dispose of. It's interesting to some because thorium is _very_ plentiful. So does it have less waste? If it is on par with uranium but there is a ton of it I would say that's a reason to look in to it more. I know of one company on the market and its trading OTC (THPW) so it doesn't seem like many are mining it at all.Life is all about ass....either you're kicking it, kissing it, working it off, or trying to get a piece of it. Muff Brother #4382 Dudeist Skydiver #000 www.fundraiseadventure.com Quote Share this post Link to post Share on other sites
billvon 2,454 #31 November 3, 2009 >So does it have less waste? No. Its burnup ration in light water reactors is lower, so you need more fuel for the same energy (= more waste per megawatt-hour.) Quote Share this post Link to post Share on other sites
SimonBones 1 #32 November 3, 2009 Quote in our existing reactor the refueling cycle is every 18 months, 1/2 of the fuel is replaced, fuel rods are stored on-site either in the pool or dry storage You can go much much longer than that if your fuel is enriched to 97% 108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites
Lucky... 0 #33 November 3, 2009 Quote Do you work with Gay male porn stars? Do you PA much? Quote Share this post Link to post Share on other sites
billvon 2,454 #34 November 3, 2009 >You can go much much longer than that if your fuel is enriched to 97% . . . There are one or two practical problems with that approach . . . Quote Share this post Link to post Share on other sites
SimonBones 1 #35 November 3, 2009 Sure there are pros and cons to every type of design. That doesn't mean it isn't currently being done successfully in some types of currently operating reactors.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites
Lucky... 0 #36 November 3, 2009 Quote Quote Quote nuclear power pays my bills and funds my skydiving addiction! Do you work with Homer Simpson? how do you know!? Doh! I'm sure you hear that a lot Quote Share this post Link to post Share on other sites
billvon 2,454 #37 November 3, 2009 >Sure there are pros and cons to every type of design. Of course. But a guaranteed massive explosion caused by a single operating error makes it a poor candidate for commercial nuclear power. In a carefully controlled military or research setting, it may make sense though. In general I think it's a mistake to design commercial reactors such that they can easily go prompt-critical. (Chernobyl is a case in point there.) Positive void coefficients are likewise a good thing to steer clear of. Quote Share this post Link to post Share on other sites
SimonBones 1 #38 November 3, 2009 What??? It can easily be done without risking prompt criticality! Just cause Chernobyl was an older poorer design (which had many of its safety features removed during the incident) doesn't mean it can't be done safely. If you limit rod speeds and have scrams based on rate of power change (and a few other protections against rapid reactivity insertion) than it shouldn't even be an issue. Besides, there are still several operational Chernobyl reactors today that didn't have all those nasty problems considering the awful design. Most civilian reactors just don't need many of the pros that come with high enrichment like more responsive changes in power levels etc. But would probably still benefit some from refueling less often and creating less volume of high level waste. How much does refueling cost, about a million a day I believe? Guaranteed massive explosion? Pffft. Come one now. It's been used over and over again for decades without issue considering the many operating errors I've seen 108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites
Belgian_Draft 0 #39 November 3, 2009 Quote >Sure there are pros and cons to every type of design. Of course. But a guaranteed massive explosion caused by a single operating error makes it a poor candidate for commercial nuclear power. In a carefully controlled military or research setting, it may make sense though. In general I think it's a mistake to design commercial reactors such that they can easily go prompt-critical. (Chernobyl is a case in point there.) Positive void coefficients are likewise a good thing to steer clear of. Oh, c'mon, Bill. Chernobyl almost worked! HAMMER: Originally employed as a weapon of war, the hammer nowadays is used as a kind of divining rod to locate the most expensive parts adjacent the object we are trying to hit. Quote Share this post Link to post Share on other sites
billvon 2,454 #40 November 3, 2009 >Most civilian reactors just don't need many of the pros that come with >high enrichment like more responsive changes in power levels etc. And the 30+ year lifetime without refueling. >Guaranteed massive explosion? Pffft. Come one now. One of the problems with very highly enriched cores is that they have reactivity to spare, and thus can achieve much higher maximum power outputs than a low-enrichment reactor can. Indeed, that's one of their big strengths - as reactivity declines, you have a lot more control (changing rod insertion, changing moderator mix, moving reflectors etc) to get that reactivity back. With that control comes the ability to increase power when you _don't_ need it. And at those power levels (which can reach many times above the reactor's rated power) the issue of "rapid disassembly" (love that euphemism) is a big one. You can get around that problem via design, of course - but it's a lot harder to make a highly enriched reactor passively safe. Which is why the LEU designs are much more common. Heck, Canada has a reactor design that can operate with _natural_ (unenriched) uranium, and they've had good luck with it. From a proliferation standpoint that's pretty ideal. >But would probably still benefit some from refueling less often and creating less >volume of high level waste. How much does refueling cost, about a million a day >I believe? Agreed there. But what would it cost to guard weapons-grade uranium the entire time the plant is operating? Losing 100 kilos of that stuff is a lot more serious than losing 100 kilos of LEU. Quote Share this post Link to post Share on other sites
kelpdiver 2 #41 November 3, 2009 Quote Guaranteed massive explosion? Pffft. Come one now. It's been used over and over again for decades without issue considering the many operating errors I've seen If you've personally seen many operating errors, that's a pretty good argument against designs that have more severe consequences when things go wrong. I also wonder how many accidents have occurred in military applications that have not been disclosed publicly, both by our own forces, and by others. Quote Share this post Link to post Share on other sites
warpedskydiver 0 #42 November 4, 2009 Are we missing a submarine and its crew? Are we missing a Carrier and its crew? Quote Share this post Link to post Share on other sites
virgin-burner 1 #43 November 4, 2009 chernobyl was a test gone wrong, running the reactor well outside its parameters because a *major* dickhead did it because he could; he was the chief in charge! bad example..“Some may never live, but the crazy never die.” -Hunter S. Thompson "No. Try not. Do... or do not. There is no try." -Yoda Quote Share this post Link to post Share on other sites
kallend 1,661 #44 November 4, 2009 QuoteAre we missing a submarine and its crew? Are we missing a Carrier and its crew? Thresher... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
warpedskydiver 0 #45 November 4, 2009 Other than Thresher, we have not lost any crew due to a reactor failure. One out of how many sorties by Nuclear powered vessels? How many millions of miles? Quote Share this post Link to post Share on other sites
SimonBones 1 #46 November 4, 2009 The Thresher sinking was not related to any kind of nuclear accident. They took on a seawater leak at test depth which in turn grounded some vital electrical equipment that initiated a reactor safety shutdown. The shutdown of the reactor was coincident to their situation at hand. In an attempt to blow their ballast tanks, moisture in the high pressure air lines froze and stopped up the air pipes which caused a failure in the ability to emergency surface. Had the reactor not shut itself down, they probably still would have sunk. This was not a problem with reactor operation, the reactor did what it was supposed to do sensing a problem. This was a QC problem with welding sea water piping inside the sub and moist air where it shouldn't have been. The nuclear sub USS Scorpion also sunk for reasons unrelated to nuclear operations.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites
warpedskydiver 0 #47 November 4, 2009 When I said failure I meant that they had no power to use in their attempts to save themselves. I have actually met with some old sailors who were involved in the search for the Thresher. Very sad, and they still feel bad about it. The families waiting upon the docks... Quote Share this post Link to post Share on other sites
billvon 2,454 #48 November 4, 2009 >chernobyl was a test gone wrong, running the reactor well outside its >parameters because a *major* dickhead did it because he could; he was >the chief in charge! Uh, no. It was a critical safety test; without a successful test, they had no way to prove they could shut the reactor down safely during a complete power failure. It had been planned for years, ever since the reactor opened. In fact, they had tried it several times before, but electrical problems prevented the test from being successful. During this particular test, xenon poisoning decreased available reactivity, and the control rods had to be almost completely withdrawn to maintain the desired power level. This led to an unstable condition where the formation of steam voids increased reactivity so rapidly that control rod insertion could not happen quickly enough to control the reaction. The test proceeded as expected until the operators started the SCRAM system, which is intended to shut down the reactor. As part of the SCRAM, control rods were inserted. This displaced coolant and greatly _increased_ reactivity. Power spiked to around 30GW, coolant flashed to steam, and the reactor exploded. One of the big problems is that the very thing that should have shut the reactor down - the SCRAM system - actually caused the accident. Another problem was that they were ignoring a lot of warning signs (reactivity way too low before the test) that, in retrospect, would have been obvious to the primary operating team - but the test had gone long and they had gone home. All of which are good examples of why RBMK reactors aren't that safe as commercial reactors. Quote Share this post Link to post Share on other sites
kelpdiver 2 #49 November 4, 2009 QuoteOther than Thresher, we have not lost any crew due to a reactor failure. One out of how many sorties by Nuclear powered vessels? How many millions of miles? As I wrote: I also wonder how many accidents have occurred in military applications that have not been disclosed publicly, both by our own forces, and by others. It may be difficult to conceal a lost sub in the US, but we also were told that Pat Tillman died in a fight with the enemy, and that Jessica Lynch was a heroine, and that's recent history. Soviet history seems murkier, and with more mishaps. US history has enough MUF incidents that the use of HEU gives concerns. In general, I subscribe to a KISS approach, so I don't go looking for more failure points. Quote Share this post Link to post Share on other sites
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