| Your thoughts on nuclear power...
Posted: 7/19/2007 2:30:50 PM | | Having a half life of 11 seconds (like F-20) is really nice, wait an hour or so and all the radioactivity is gone. A few isotopes have half lives that are a function of the environment they are in, typically they decay by K electron capture (I believe). For everything else, the only way we presently know of to alter the decay of a radioactive species, is to force it into some other nuclear reaction. But if we toss a mole (6E24) atoms into a nuclear reactor for some reasonable length of time, we might only activate (neutron capture most likely) 1E12 nuclei. On a chemistry or mass basis, we (essentially) haven't altered any of the matter. Now, if we could find a way to modify even 10% of the nuclei, we could probably design a process to "burn" radioactive nuclei. So, part of the idea is that if we don't "permanently" dispose of waste, if we do find this magic we can reprocess all the waste and make it go away. So far, we haven't had much luck. | |
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| Your thoughts on nuclear power...
Posted: 7/19/2007 8:51:13 PM | Oh, on the solar cell topic. 2007/05 Advanced Materials and Processes has an article on photovoltaics. They give a useful insolation (wrong word?) of about 700 W/m^2 (about 51% of the 1370 that hits the upper atmosphere). The article goes on to state that if you wanted to power the US with solar cells, you need all of Pennsylvania plus all of Rhode Island.
I actually though State College was a nice place, so I wouldn't want to put solar cells there (I went to school at C-MU for a while). The waitress at the restaurant I ate at all the time got married in State College. Pittsburgh, sure turn it into solar cells. :-) I never could figure out how Pittsburgh was the most livable city in the US when I was going to school there. | |
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| Your thoughts on nuclear power...
Posted: 7/20/2007 6:25:02 AM |
The article goes on to state that if you wanted to power the US with solar cells, you need all of Pennsylvania plus all of Rhode Island.
Found this image on wikipedia's article on solar power:
http://en.wikipedia.org/wiki/Image:Solar_land_area.png
When I mentioned Rhode Island I was thinking of this image (black spots represent required surface area to completely power a given land mass) and somehow remembered the black spots being smaller >.< maybe I need my glasses checked.
Full article: http://en.wikipedia.org/wiki/Solar_power
One thing I've thought about is floating solar arrays which we could place out off the coasts so as not to cover land surface area which could be used for living/agriculture/industry etc. We'd just have to study its effects on the marine ecosystem to stave off the activists, but it's feasible and probably only marginally more expensive than building them on land.
But since the sun only shines for half a day and the cost of storing that much power for night use would be astronomical (no pun intended) solar power could only at best augment other power sources, which brings us back to nuclear power. | |
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| Your thoughts on nuclear power...
Posted: 7/20/2007 10:24:05 AM | | Solar power also wouldn't be practical for some parts of the world which get less sunlight than say others by the equator. We should be trying to solve nuclear fusion, as that is best the power source in theory. | |
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| Your thoughts on nuclear power...
Posted: 7/22/2007 3:55:46 PM |
With respect to all radioactive waste being in dry casks, I thought at least some irradiated fuel elements were stored in swimming pools (at reactors, not for people). I should've clarified myself better. You are absolutely correct. The spent fuel is first stored in pools onsite, and after (I think a year or two) the fuel has "cooled-down" (radioactivity reduced) significantly and can then be stored in the dry casks. Thank you for the correction.
Sorry if this has been mentioned already, but if it hasn't, I continue to wonder why build holding sites for nuclear waste when we already have them? Drop the stuff in the holes made by earlier bomb tests, and though a pain would likely be recoverable if another use was found. Or has this already been dismissed for some reason? It's interesting to note that you have come up with this idea without looking through previous posts (I assume according to your choice of words). The proposed site in the US, Yucca Mountain, was previously a test site. Although, the idea is not to stick the waste into holes made by bombs, but to build a well engineered underground facility.
http://www.ocrwm.doe.gov/ym_repository/index.shtml | |
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| Your thoughts on nuclear power...
Posted: 7/24/2007 10:54:16 AM | | Having played the odd game in hot-atom chemistry (Szilard-Chalmers effect), one thing I've wondered about ever since they discovered buckyballs, is this a useful thing for nuclear fuel? Stick a fissile species inside the cage of a buckyball. The fissile species is then soluble in organic solvents like benzene. If the fissile nucleus reacts, it breaks the cage. The fission fragments may break other cages near them, I would hope they wouldn't. But for the most part the fission fragments will either end up as ionic species, noble gases or carbides (reactions with buckyball cage fragments). If this idea has any merit at all, it could make fuel reprocessing quite easy. Whether that is good or bad is another thing. Or, a person could put a breedable species in the cage, and after exposure to a core, we have the now fissile species that can be separated quite easily. Mind you, the buckyball cage would have to be able to withstand the alpha decays that accompany some of these breeder reactions. | |
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| Your thoughts on nuclear power...
Posted: 7/24/2007 4:35:20 PM | | Arrgh, I think I had a brain fart there. Are there any fissile nuclei generated via alpha decay? Pu-239 and U-233 would only involve beta decay, and I suspect beta decay isn't going to cause any problem to a buckyball cage. | |
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| Your thoughts on nuclear power...
Posted: 7/24/2007 7:37:46 PM | A friend told me once that "caging" radioactive material in a buckyball effectively blocks the radiation. Since I changed my major from physics to computer science I really don't have a clue whether this is the case or what special circumstances may be involved however.....
With the myriad types of nanotubes being produced and discovered, it seems to me that it's possible we may discover a species of nanotube that floresces in the visible spectrum when exposed to higher frequency photons. These could be incorporated into the buckyball above so that the radiation from your isotope is essentially converted into a light source. High frequency photo-electric nanotubes would also be quite useful. But this is all dependent upon the reality of my first statement. Wouldn't it be nice... | |
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| Your thoughts on nuclear power...
Posted: 7/24/2007 9:14:27 PM | C-60 (the original buckyball) isn't big enough to cage all atoms. Buckyballs (at least the unhydrogenated variety) have most of their bonding as some kind of resonant structure similar to benzene. This resonant structure is apparently the reason why benzene is quite radiation hard. However, bake it in enough gammas, and it still turns into coke. So, being resistant doesn't mean it is radiation proof. I really can't see the buckyball cage as doing a darned thing to a beta. It is just a lonely electron, and it is traveling fast. Now whether a buckyball can contain an alpha particle or a fission fragment is another question.
I can't see a buckyball as having any effect on a gamma photon, but it might on low energy x-rays or Auger electrons.
I had run into another materials paper about nanotubes, and it seemed to me that a person could construct a positron source by putting a nugget of Na-22 or similar at the base of each of an array of nanotubes. There may very well be a tendency to align the propagation direction of the positrons. If there was some way to fix the ground state of all the nanotubes to being the same (nanotubes attached to a graphite plane?), the resulting positron emission might even be correlated from tube to tube in the array.
I would think that you would need a metal atom inside each nanotube in order to get any kind of photo emission. But, perhaps all you need is to mess around with the bonding in each tube. Another paper talked about changing from 6 fold bonding for each carbon atom, to arrays of 5, 7 or 5/7 bonding. | |
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| Your thoughts on nuclear power...
Posted: 7/29/2007 8:14:58 AM | Buckyballs/fullerenes and radiation.
I am finding references to medical studies involving the ability of fullerenes to absorb electrons from free radicals, and hence cut down on the effect of radiation in biological systems. The only things I am seeing so far with respect to direct interactions with ionizing radiation are a couple of patents, and the patent system is so darned screwy that you can't trust that.
I will keep looking for something on the physics side of radiation interactions. | |
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| Your thoughts on nuclear power...
Posted: 7/29/2007 1:48:26 PM | "I'm curious to know what the general feeling is on nuclear power; specifically, what is the one greatest concern (con) that you have about nuclear power or the greatest benefit (pro) that you see coming from nuclear power and why?"
It's a stop gap solution at best. The problem is radiation and waste management. What we need to see is techologies like fuel cells and greaseal engines come to the fore front. The only good that really comes from them is that they are a cheap source of fuel and they help reduce the nuke weapons stockpile.
I have a feeling that if someone were to find a way to convert the biomass and other materials from landfills into useable fuels and raw materials then we would have something. Think about it, how much would it cost to buy a landfill. I'm willing to bet you could get one very cheap before they become a hot commodity. | |
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| Your thoughts on nuclear power...
Posted: 7/29/2007 2:34:17 PM | More on buckyballs. I did run into a paper on the radiolysis of C60 dry and wet from gamma radiation. They were interested in the cosmic population of C60, asteroids, comets and stuff. C60 is very resistant to damage by gamma photons, and wet environments cause more damage than dry. Polymerization seems to be the predominant mechanism.
As far as making energy out of the waste mass of civilisation - where I would start are some of the very interesting organisms we are finding in hot water, such as vents in the ocean and at Yellowstone. In places where geothermal energy can be used to keep a "pool" hot, I wonder if some of these organisms couldn't process a broad spectrum of waste. With the elevated temperatures, kinetics could be quite high. | |
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| Your thoughts on nuclear power...
Posted: 7/29/2007 6:47:23 PM | "As far as making energy out of the waste mass of civilisation - where I would start are some of the very interesting organisms we are finding in hot water, such as vents in the ocean and at Yellowstone. In places where geothermal energy can be used to keep a "pool" hot, I wonder if some of these organisms couldn't process a broad spectrum of waste. With the elevated temperatures, kinetics could be quite high."
The problem with something like that is containment. Any organism you introduce to another environment has to be contained or it could wreck the ecosystem if introduced to the wrong area. The best bet I've seen so far is what they have been doing with e-waste and other mixed material goods. The crush things down to a fine mix and then sort them out to be smelted. At high enough temps most things breakdown to elemental compounds. The trick is preventing any resulting pollution from becoming a problem, as well as sorting out the materials......
If you could sort out the biomass and burn it at a high enough temp it could possibly be used to fuel a steam turbine. They use similar tech with old rubber tires. | |
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| Your thoughts on nuclear power...
Posted: 7/29/2007 7:01:45 PM | "One thing I've thought about is floating solar arrays which we could place out off the coasts so as not to cover land surface area which could be used for living/agriculture/industry etc. We'd just have to study its effects on the marine ecosystem to stave off the activists, but it's feasible and probably only marginally more expensive than building them on land.
But since the sun only shines for half a day and the cost of storing that much power for night use would be astronomical (no pun intended) solar power could only at best augment other power sources, which brings us back to nuclear power."
The trick with solar energy is that it has to be converted to another form before it is usable, realistically we need some kind of conversion system similar to chloroplasts to make it really work. Possibly if we had an engine that could be powered by the sugars produced then power could be generated or if we could directly draw power via chemical conversion or thermal conversion then we have something. Organic batteries....... Just grow them, harvest them and plug them into the grid. | |
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| Your thoughts on nuclear power...
Posted: 7/29/2007 8:26:03 PM | | I was thinking of a self-contained pool, not an existing hot geothermal water source. Nature doesn't build much that is self-contained, everything communicates to everything else. Works fine for evolution, not so for experiments. | |
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| Your thoughts on nuclear power...
Posted: 7/30/2007 9:23:30 AM | "I was thinking of a self-contained pool, not an existing hot geothermal water source. Nature doesn't build much that is self-contained, everything communicates to everything else. Works fine for evolution, not so for experiments. "
That could work. You would still have to sort out the biomass from the rest of the waste to get a good reaction though. Personally, when you first mentioned it I had visions of directly applying it to the landfill.
Granted there is some commuication within the global ecosphere, however there are multiple ecosystems within any particular area. If something gets introducted in the wrong area you could have an inbalance of in the system. In cases like that extinction not evolution takes place. | |
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| Your thoughts on nuclear power...
Posted: 8/1/2007 9:12:52 AM | Thermal bacteria pools - actually, I don't think the sorting need be too rigorous. You could probably do a rough sort by magnetic properties and then one on density for the non-magnetic material. The bacteria in the pools would be tailored for what they are digesting.
Just about any discussion looks at replacing one kind of generator with something else. I just read a blurb about nuclear and solar, which said that if one looked at putting a nuke in Nevada, the size of the property needed for a 2 GW reactor would also receive about 800 MW of solar.
What would happen if we put some kind of solar stuff up at any kind of existing plant? Nukes, coal, natural gas, hydropower, whatever. The land is already not being used for aesthetic purposes, adding solar can't make them look worse. You probably need to have some kind of storage (flywheel, batteries, capacitors or something) to level out the solar, but that can go underneath other stuff. In the case of existing fossil fuel generators, you can cut down on the fossil fuels burned in the daytime, when demand is high. You might even level the output from the fossil fuel side, allowing it to operate closer to optional more of the day. | |
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| Your thoughts on nuclear power...
Posted: 8/18/2007 1:47:10 AM | Where to begin...... Co-generation is one of the true forms of energy conservation in effect today. This clean, safe and ridiculously stable form of energy is, at it's worst fantastic. It's unfortunate that it has gotten a bad rap from some industry leaders in the energy constituent. The fact that the rod's never actually come in contact with the BFW (boiler feed H2o) means even more environmental protection. The only problem, as stated earlier, is the disposal of spent rods. Even as we speak, scientists are developing new and ground breaking techniques to stabilize and safely dispose of these things that produce such a clean and plentiful supply of, what I like to call, the cities life blood. Converting the energy produced to a useful transportation fuel on the other hand (with the exception of electrically powered vehicles) is just about useless. The heat and potential energy created from the fission process is far to much for the average JOE to try and troubleshoot (not that the process is all that complicated, but it should be left to professional operators). Our military has caught on to this and is currently using nuclear fuel for our most important of goals, preserving the freedom necessary to further study the capabilities of this wonderful element.
Sincerely
An oilman.
Platform Gail, Santa Barbara Channel.
S | |
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| Your thoughts on nuclear power...
Posted: 8/18/2007 6:47:19 AM | | Nothing wrong with nuclear power. It is quite safe actually. Course I will be working on a nuclear reactor in a naval vessel here soon. | |
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| Your thoughts on nuclear power...
Posted: 9/21/2007 10:26:45 AM | Seems that we are getting closer to a full revival...
In mid-May, the Tennessee Valley Authority successfully rebuilt and restarted Unit 1 of the Browns Ferry Nuclear Plant, a five-year, $1.8 billion effort that came in on time and on budget. The reactor, which went into service in 1974, was shut down in 1985 after a series of problems, including a fire.On Aug. 1, the TVA agreed to complete work on Unit 2 of Watts Bar, a project that was suspended in 1985. http://www.nei.org/newsandevents/newsreleases/neicongratulatestva/
Federal regulators, girding for explosive growth in the nuclear power industry, say they are weeks away from an anticipated flood of license applications for new reactors not seen since the 1970s. http://ap.google.com/article/ALeqM5imdFxeQBkMYCZEzkiu0Nts0n-MRA | |
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| Your thoughts on nuclear power...
Posted: 9/24/2007 5:08:09 PM | Alberta is looking at a bigger Candu in part to help with oilsands development. And I've seen one anti-nuke from Saskatoon who thinks she successfully tossed an application to install a SLOWPOKE Energy System there a few years ago, who is gearing up to fight this Candu which has got to be a 12 hour drive from where she lives. The watershed of the river this Candu would be on, isn't even remotely close to where she lives either.
Engineers aren't infallible, we occasionally make mistakes (which we are still liable for). We do try to analyze things from independent points of view so as to minimize the chance of mistakes. With respect to Candu performance in Canada (which is mostly in Ontario), I think that most of the problems they see are due to Ontario Hydro re-engineering stuff that had already been engineered by AECL. However, since there are few counter examples it is hard to say for sure.
In the large, we have done a fair job of engineering safe systems. Some problems have occurred, which I think in part are due to this idea that we always accept the lowest cost bidder. There are places for this kind of behavior, but there are all kinds of civil infrastructure type projects where it doesn't make sense. Environmentalists and other anti-nuclear people have brought up all kinds of arguments which sound like science, or are based on science. Rightfully, engineers are trying to address these concerns on a scientific basis. The complaints never seem to go away, in part due to a lack of trust I suspect. I think the anti-nuclear crowd in part doesn't trust engineers to do the job properly after problems are pointed out.
However, I think a far larger part of the situation is that they just don't like nuclear, for any reason. This is a political problem, and I wish they would quit trying to dress it up like a technical problem. Technical problems have been presented, thought about and studied. They will continue to be. But people who make up a problem which sounds technical, and then refuse to argue the problem in a logical and scientific manner, are just engaging in politics. Take that back to where it belongs, the political arena. | |
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| Your thoughts on nuclear power...
Posted: 9/25/2007 9:41:30 AM | | NRG Seeks First US Nuclear Plant Permit in Decades, hopefully we can break the logjam and get some modern facilities made. | |
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| Your thoughts on nuclear power...
Posted: 9/27/2007 9:24:18 PM | And now TVA too...
http://www.wchstv.com/newsroom/ky/news13.shtml
http://money.cnn.com//news/newsfeeds/articles/newstex/AFX-0013-19874787.htm | |
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| Your thoughts on nuclear power...
Posted: 9/28/2007 12:02:40 AM | | We launch enough crap into space. Why don't we just blast nuclear waste onto the moon.. nah... I don't want it to get too heavy. Well pick a nice spot here on earth for it already! Just don't disturb the earth's core. | |
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