Yes, nuclear power isn’t PC but given the choice of a new generation nuclear power plant cranking out 1 GW or a 1 GW coal fired plant, which would you pick? The nuke plant that might be an environmental disaster, but the coal plant will be. (“Clean coal” or not it would burn two train loads of coal a day (by train load I mean a train that has >150 hopper cars and 3 locomotives), and after a few years the heavy metal, and acidic oxides plume it sends up wind will build up and start to degrade the environment, oh then there is all the CO2, mining and ash to think about.) In real terms 24 tons of uranium replaces 3.1 million tons of high grade coal, with reprocessing that is only ~1,500lbs of high level waste, versus 7 million tons of CO2 (best case scenario it would take a managed forest the size of Yosemite National Park to remove that much CO2), 200K tons of SO2 (an acidic oxide), a couple tons of heavy metals and several hundred pounds of naturally radioactive materials all coming out of the smoke stack plus 200K tons of corrosive fly ash waste. (Sidenote: There is less radioactivity in released reactor coolant water than in the same amount of beer.)
The choice is yours, and don’t BS yourself thinking we don’t need more generating capacity or that renewal energy will fill the need. I have discussed base load in a previous post so I won’t go into it again, but every kilowatt that is coal or nuclear is a kilowatt that isn’t natural gas (so less to import) or hydro. (Yes, we could open dams and let rivers and fish run free, but the river will be cooling a power plant that replaces the lost hydro generation.)
Ok the clean coal people say they can capture all the emissions and so they will be carbon neutral. Um quick question what do you do with 7 million tons a year of CO2, you could carbonate a small lake with that? Assuming you can get rid of that much CO2, what does that cost? Answer me that and I will post an apology to the clean coal people. Either way it makes nuclear more competitive…
Well I would love to say Integral Fast Reactors are the future, with their short lived waste (yes the waste would make a great dirty bomb, but during the few short years it was useful stealing it would be fatal with in minutes, and processing into a weapon would be difficult because it would either melt anything it was contained and spew so must high energy radiation a Brownie troop with a radiation detector made from old fluorescent tubes could track it down) their efficient fuel use, and ability to use nearly any tranuranic element as fuel but I can’t. While liquid metal cooled reactors are essentially failsafe since the liquid metal will make convection currents and be self cooling if the external cooling fails, being a huge pool of radioactive molten sodium makes them hard to maintain. The next generation of reactors will be pebble bed which is barely critical or hopefully my favorite, supercritical steam (if you have studied your steam tables you know that above 1200 C? steam behaves like water, so rapid depressurization does not cause a steam explosion) or helium cooled. Both the supercritical steam and helium are nearly self cooling since the pressure in the reactor drives a convention current causing the hottest coolant to be forced out and sucking in “cooler” coolant. So as long as the pressure vessel is intact and the laws of physics are in effect the reactors will be cooled, whether or not the pumps work. Also they will be smaller reactors. Why smaller? They say smaller is safer but actually bigger is more efficient however they are having trouble making turbines larger (the blade tips exceed the speed of sound and that causes problems), plus small turbines can be built in a factory and trucked in, while big turbines are built onsite.
One of the biggest things against nuclear power besides the safety is the waste issue. Both what to do with the waste that no one wants and what if someone steals the waste. (The irony there is thick.) The biggest concern is that in the reactor U238 is turned into Pu239, which is nuclear fuel and nuclear bomb material, (which it is bad stuff to have lying around, since a piece the size of a grapefruit in the wrong hands could flatten a city.) However, Pu239 can be converted into Pu240 by fast neutron bombardment, which is a bad thing for bomb makers, so the fuel rods are changed frequently to prevent that from happening. Why is it bad for bomb makers? Pu240 is fissile, (there is no Pu isotope that isn't), but it is too easily fissile so a nuclear bomb made out of it fizzles instead of explodes. (I will come back to this, so keep Pu240 in mind.)
Yes, the isotopes can be separated but that defeats the whole point of using Pu for secret nuke project. The beauty of Pu is that it is easy to chemically separate from the spent fuel, so you don't have to buy lots of expensive gas centrifuges from Germany, Russia, or France, and build a huge facility to enrich uranium that the UN will freak over, and the US or Israel will bomb (like Iran, and Iraq did), etc. With normal Pu your >$10 million buys you a ready to strike a blow for Allah against infidel West nuclear pit. (Yes that is a stereotypical statement, but if it's true it's true. If the Pu you buy/steal is mixed with Pu240/242 all you end up with is a very expensive and really crappy dirty bomb.)
So what is the future?
The future to me is MOX. Mixed OXide fuel is a way to convert weapons grade Pu into slow neutron (thermal) reactor fuel, by mixing it with weakly enriched uranium. The argument against MOX is reprocessing spent fuel into MOX costs too much (uranium is so dirt cheap and plentiful in the US it is barely worth mining). Well what are the costs of one pass fuel use when the cost of Yucca Mountain is added? If we reprocess we only have to keep the waste isolated for a couple thousand years, instead of millions (making the engineering simpler) and the reprocessed waste takes up only 3% of the space of raw waste (lets make it 5% to account for reprocessing waste) so the WIP doesn’t fill up as fast.. The next argument against MOX is that stolen fuel rods can be turned into a nuke, but stolen Pu239/240 fuel rods are worth more for the zirconium housing than the Pu.
Now what about spent fuel rods? Well spent fuel is harder to get hold of because it is kept on site for a few years to cool off, so much of the dirty bomb potential is lost. That leaves the Pu in the rods, and that is a tough problem, since they have to be transported for disposal or reprocessing. How would I fix it? Well either the fuel has to be blended with Pu240 before transport, or at least tracer gases added so stolen fuel can be tracked via rare noble emissions given off during reprocessing.
Two areas I would encourage research into: First is using an “inert” filler instead of U238 to make up the bulk of the fuel rod (and therefore the bulk of high level waste), since only a small percentage of the rod is fissionable material. The inert filler could be degraded during the use of the fuel but as long as the half life was short, the filler would contribute very little waste, and facilitate waste processing. Or, if the filler was well designed it could would vitrify at high temp, so the waste could be rendered useless for weapons manufacture, or if the temperature of the reactor rose too high it would prevent the fuel from burning. Second bring back the Integral Fast Reactor. It is an almost closed cycle reactor taking in only small amounts of new fuel and its waste stream is small and can mostly be sold for medical isotopes. So, no transporting high level waste to Nevada, and no risk of proliferation since the Pu is contaminated with Pu240/242. You can thank the forward thinking John Kerry for canceling the IFR program, even though it answered all his criticisms of nuclear power.
Sorry I got tired and side tracked here at the end. Also while researching this post I found out I was not the first person to think of the Pu240 thing. (Which is a good thing because if someone as ignorant as I am is the first person to think of all this then the DOE has really been slacking.)
On last rant:
American’s have an irrational fear of radiation, if you are truly afraid of radiation, stay out of the sun, don’t eat or breath because the world around us is actually very radioactive but before you freak out, blame the earth and the sun cause it was this way when we got it, and without radiation we wouldn’t be here cause radiation keeps the mantle and core molten. Now I am not saying radiation is safe, I am just saying while you are outside protesting the building of a reactor you are exposed to more radiation from the sun, and if you were in the plant control room. Also, irradiated food is not still radioactive; the gamma rays from the Co60 pass through the food like a hot knife through butter, and destroy the DNA of bacteria, killing them. The amount of damage done by radiation to the nutritional content of the food is nothing compared with the damage you will inflict when you cook it. Now for all the reactionaries pick one: Giving someone you love irradiated food, or a fatal case of food borne illness? E coli O157:H7 is out there and kills dozens of people a year mostly young children, and is spread by eating raw vegetables (especially ones grown organically with umm natural fertilizers) more than undercooked meat.
I will leave you with this thought: if you have ever eaten out or bought prepared food you can eaten irradiated food.
No comments:
Post a Comment