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Post by rick123456 on Aug 21, 2013 8:55:59 GMT 9.5
Cyril, I reviewed the Cs-137 half life of 110 days. Would you review my statements following as I am not good at relation ship of half life to radiation exposure over a time period. *Living in a radioactive area like Fuku... , as a hypothetical, a person would collect radiation in their body at Z micSv/day for 110 days so totals to Z x 110 micSv/days = (110Z)micSv/110days total, on the other hand it decays each day by Y%/runing total for 110 days. I have used a spread sheet to get an estamate with assumtions and it leans to the fact that half life of 110 days is close to zerro. It seems that the added radiation per day is much greater then what decays each day. Like I say I may be way off, take a look and see what you come up with. thanks, Rick
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Post by cyrilr on Aug 21, 2013 20:06:12 GMT 9.5
Health effects of plutonium? There appear to be none. Here's a nice discussion we are having: www.energyfromthorium.com/forum/viewtopic.php?f=2&t=4152The guy received 64000000 microSieverts of dose, all from plutonium. The most deadly type, the Pu238. And a type that doesn't exist in nature, highly soluble plutonium nitrate. The type that gets in your bones and supposedly causes great havoc there. The LNT model predicts that this guy should have died 4 times over from cancer from this radiation. Actually he didn't get any cancer. Funny. The results were the same for the other test subjects. What does this tell us about plutonium and about the LNT model?
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Post by edireland on Aug 22, 2013 1:29:12 GMT 9.5
Plutonium Nitrate would exist in nature in certain circumstances, such as a leak from a reprocessing plant.
But in the case of a catastrophic chernobyl esque core accident it is correct that it would not.
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Post by jagdish on Aug 22, 2013 16:30:56 GMT 9.5
Existing processing is a continuation of plutonium extraction for weapons. For reactor use we should adopt pyroprocessing using chloride volatility and electrolysis. Solution based processing involves too much of fluids which will leak later. High temperature processing leaves mostly solids after cooling for some time, which can be put away till required again.
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Post by rick123456 on Aug 22, 2013 16:53:18 GMT 9.5
Cyril, They used Pu239 and Pu238 but common from NPP blow up is Pu239 and Pu240, Pu240 is the most hazardous of these because half life under 14 years. The main hazard from NPP radiation is inhaled over time not acute like the guy mentioned. The
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Post by rick123456 on Aug 22, 2013 16:56:27 GMT 9.5
Cyril, They used Pu239 and Pu238 from weapons but common radiation from NPP blow up is Pu239, Pu240 and Pu241 , these produce americium241 and about a dozen other isotobes that are hazadouse. The study has very little to do with NPP radiation, it takes a while but study Pu239-240-241 and all their daughter products and their daughter products and you will gasp at the hazards. It is hard to find studies on some daughter products to know how hazardest they are. For your infermation when looking into it is the shorter the half life the more hazardest it is. All so most studies by pro-nuclear in air breathed in to lungs always assumes that radiation is equaly distributed in the air showing it will take huge volums of air or water to be ahazard. This is why the antinukes and pro-nukes are so far apart in evaluating hazard from NPP.
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Post by rick123456 on Aug 22, 2013 17:23:33 GMT 9.5
Cyril, I forgot to add this, as you pointed out before that Pu has a shorter bio half life so the test injecting into the blood would greatly reduce the half life because it did not go through digestion or lungs so pathway should be shorter pissing it out sooner.
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Post by edireland on Aug 22, 2013 18:13:36 GMT 9.5
Existing processing is a continuation of plutonium extraction for weapons. For reactor use we should adopt pyroprocessing using chloride volatility and electrolysis. Solution based processing involves too much of fluids which will leak later. High temperature processing leaves mostly solids after cooling for some time, which can be put away till required again. Come back when you obtain sufficiently high seperation factors to make pyroprocessing practical for LWR use. FLUOREX is probably the best reprocessing technology that is practical for LWRs at the present time, as it avoids the conversion steps for most of the uranium, allowing reduced cost re-enrichment (potentially on site at the reprocessing plant).
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Post by edireland on Aug 22, 2013 18:23:33 GMT 9.5
Cyril, They used Pu239 and Pu238 from weapons but common radiation from NPP blow up is Pu239, Pu240 and Pu241 , these produce americium241 and about a dozen other isotobes that are hazadouse. The study has very little to do with NPP radiation, it takes a while but study Pu239-240-241 and all their daughter products and their daughter products and you will gasp at the hazards. Pu-239 primarily decays by alpha emission, producing.... U-235. Which has a far longer half life than the Plutonium does and has radiotoxicity that is swallowed up by its chemical toxicity. Pu-240 primarily decays by alpha emission, producing a very long lived isotope U-236. Not quite as long lived as U-235 is but still very long lived. Only Pu-241 decays to something nasty, but that is a very small fraction of reactor grade plutonium. Which has a half life It is hard to find studies on some daughter products to know how hazardest they are. For your infermation when looking into it is the shorter the half life the more hazardest it is. All so most studies by pro-nuclear in air breathed in to lungs always assumes that radiation is equaly distributed in the air showing it will take huge volums of air or water to be ahazard. This is why the antinukes and pro-nukes are so far apart in evaluating hazard from NPP. So we have a catastrophic core breach accident and yet the gaseous fission products are not heated in the slightest and thus do not column, instead forming a very very thick cloud around the plant? The only major threat is the short lived radioiodine isotope which is protected against by Saturated KI solution (or tablet based) prophylaxis which is very cheap. (I once calculated you could buy the entirety of the UK the requisite 90 day course for a few tens of millions of dollars, could be stockpiled for use in case of a reactor accident)
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Post by cyrilr on Aug 23, 2013 4:06:07 GMT 9.5
Pu238 has a short half life and lots of hazardous daughter products. Yet the guy I referenced got a massive dose of 64000000 microsieverts from Pu238 plus its daughers (yes these get counted along for your information) yet the guy did not have any cancer or any other radiation related illnesses.
Rick tells us the daughter products are dangerous. So my reference to this guy who got terrible amounts of daughter products radiation, more than any other person in recorded history, but did not get cancer, discredits the idea of hazardous daughter products. Pu238 is shorter lived than a mix of Pu239, Pu240, and Pu241 that you get from weapons or reactor grade plutonium. It follows that weapons or reactor grade plutonium produces less daughter products per unit time than Pu238 from cyclotron deuteron bombardment, as this guy had got administered.
What is hazardous is dose rate. Not dose. Dose means nothing without unit time. Nuclear bombs produce deadly radiation not because of dose but because of dose rate; everything is released in a second or so, that means huge doser rate per hour (micro or millisievert/hour). Same with x-rays.
It is not different from anything else. Take 365 pills of aspirin and your life is in danger. Take 1 pill per day for a year and you get the same dose but actually a positive health effect (the acid in aspirin is good for you in small amounts). Same dose.
Nuclear power is benign because its dose is not prompt, but chronic. Even in a nuclear accident far beyond the design of a nuclear powerplant (like Fukushima) the dose rate in millisieverts/hour is tiny. Don't be fooled by total dose. This is linear no threshold nonsense, an artifact from a nuclear bomb study where all prompt radiation led the world at large to believe that there's a linear dependency between dose and damage. Completely ignoring the most important factor - dose rate.
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Post by RogerClifton on Aug 26, 2013 17:12:33 GMT 9.5
For reactor use we should adopt pyroprocessing using chloride volatility and electrolysis. [we need] sufficiently high separation factors to make pyroprocessing practical for LWR use. FLUOREX is probably the best reprocessing technology that is practical for LWRs ... Jagdish spoke of electrolysis of used LWR fuel in a chloride melt, as has been discussed elsewhere on BNC. Here, the first, majority deposit on the cathode is the still-enriched uranium, ready for re-enrichment for LWR use. The second, minor deposition is the U-Pu amalgam in the cadmium cathode, appropriate for reuse in fast reactors. This seems to me like "sufficiently high separation factors to make pyroprocessing practical for LWR use". Am I missing something?
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Post by jagdish on Aug 26, 2013 17:38:10 GMT 9.5
Reactor fuel is almost always a combination of actinides, except for enriched uranium. Used uranium fuel will have transuranics, mainly plutonium, which also need some uranium/thorium for the right combination. Thorium fuels will have U-233. Fertile U-238 from uranium or fissile U-233 can be partitioned from used fuel by chloride volatility. Thorium-U233 or Uranium-Pu plus transuranics can be combined for a reactor fuel making adjustments for lower separation factor as analysis in a lab is possible. Chloride volatility will get sufficient separation for rector use. Reactor grade plutonium is, of course, a combination of fissile Pu239 with other fertile isotopes.
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Post by cyrilr on Aug 26, 2013 19:46:57 GMT 9.5
Plutonium Nitrate would exist in nature in certain circumstances, such as a leak from a reprocessing plant. But in the case of a catastrophic chernobyl esque core accident it is correct that it would not. The thing is that the plutonium nitrate used in reprocessing plants has no concentrated decay heat source to spread it to the greater environment. The Chernobyl accident did have that concentrated heat source, plus heat from graphite-steam reaction, plus the large initial high temperature heat present from the initial criticality accident. Despite that worst case of worst case of worst cases, less than 3% of the plutonium could out of the reactor building, and almost all of what got out stayed close to the plant.
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Post by edireland on Aug 27, 2013 9:17:34 GMT 9.5
[we need] sufficiently high separation factors to make pyroprocessing practical for LWR use. FLUOREX is probably the best reprocessing technology that is practical for LWRs ... Jagdish spoke of electrolysis of used LWR fuel in a chloride melt, as has been discussed elsewhere on BNC. Here, the first, majority deposit on the cathode is the still-enriched uranium, ready for re-enrichment for LWR use. The second, minor deposition is the U-Pu amalgam in the cadmium cathode, appropriate for reuse in fast reactors. This seems to me like "sufficiently high separation factors to make pyroprocessing practical for LWR use". Am I missing something? Fast reactor fuel is useless when we will likely not have a squadron fleet of fast reactors to use it. Plutonium and uranium will have to be recycled in light water reactors. (At best maybe RMWRs) FLUOREX is the best process that can produce LWR usable materials. In that electrolysis process you will end up with a fission product contaminated metallic product which is of no use in an LWR.
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Post by Roger Clifton on Aug 27, 2013 9:56:20 GMT 9.5
Plutonium can only be recycled in a light water reactor while there is Pu239 to burn. The accumulation of Pu240 eventually becomes a neutron poison.
Could we have a link to the FLUOREX process please? I couldn't find anything on the web.
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Post by jagdish on Aug 27, 2013 14:58:25 GMT 9.5
Used LWR fuel is choking up the progress of nuclear power. It is time to recycle it. Fast rectors ate the real next generation reactors. Gen-IV reactors ideas are mainly fast reactors. IFR concept is based on fast reactors. Processing of used fuel and fast reactors are the future of nuclear energy. Fast MSR is an even better idea. If the major uranium producers Australia, Kazakhstan and Canada want to start off with fast reactors, they could have a few Enriched uranium fast reactors like the Russian SVBR. www.hitachi.com/rev/archive/2001/__icsFiles/afieldfile/2004/06/08/r2001_03_106.pdf---is the only link I could get to Fluorex. Pyro-processing might be the economical for reuse as nuclear reactor fuel.
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Post by cyrilr on Aug 27, 2013 16:44:06 GMT 9.5
Aug 27, 2013 9:17:34 GMT 9.5edireland said:
Aug 26, 2013 17:12:33 GMT 9.5 RogerClifton said: Jagdish spoke of electrolysis of used LWR fuel in a chloride melt, as has been discussed elsewhere on BNC. Here, the first, majority deposit on the cathode is the still-enriched uranium, ready for re-enrichment for LWR use. The second, minor deposition is the U-Pu amalgam in the cadmium cathode, appropriate for reuse in fast reactors.
This seems to me like "sufficiently high separation factors to make pyroprocessing practical for LWR use". Am I missing something? Fast reactor fuel is useless when we will likely not have a squadron fleet of fast reactors to use it. Plutonium and uranium will have to be recycled in light water reactors. (At best maybe RMWRs)
FLUOREX is the best process that can produce LWR usable materials. In that electrolysis process you will end up with a fission product contaminated metallic product which is of no use in an LWR. -----------------------------------------------------------------------------------------------------------------------------------------------
Disagree completely. LWR fuel recycling is more about a once or twice more passes, causing downgrading of the plutonium quality. Then the plutonium can't be economically used in any reactor, including fast! Moreover it does little to reduce long lived wastes and produces highly problematic aqeous wastes. Those are the worst types of wastes due to their mobility, corrosivity and volatility. Fluorex is even worse in this regard.
If we want a future fast plutonium or thermal thorium reactor fleet, the thing to do is immediately stop recycling fuel for LWRs. It's not even recycling, more like squeezing a small amount of added energy out of the fuel. In stead of using 0.5% of the theoretical energy of the natural uranium, you use 0.7%. Hardly impressive.
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Post by edireland on Aug 27, 2013 21:53:40 GMT 9.5
Plutonium can only be recycled in a light water reactor while there is Pu239 to burn. The accumulation of Pu240 eventually becomes a neutron poison. Yes, at which time the plutonium should be stored pending the deployment of a significant fleet of epithermal or fast reactors capable of destroying it. This is why the French are storing their spent MOX fuel rather than reprocessing it en-masse. In fact an RMWR may be able to eat 35% fissile Plutonium (spent MOX grade) and 237Np with ease and without requiring absurd dilution levels. Could we have a link to the FLUOREX process please? I couldn't find anything on the web. Its hard to find exact information on, although it is mentioned in various IAEA TECDOCs. This is something I found about it a while back, HItachi are developing it along with their fast spectrum BWR. I have seen studies that suggest that a future fast reactor could operate using entirely Pu-240 makeup assuming it was given a sufficient fissile startup feed. Remember that Pu-240 is a "neutron poison" in the same way that U-234 is, absorbing a neutron makes it fissile again, unlike some other poisons. The primary reason that multiple recycle is problematic in LWRs is because the increasing plutonium fraction drives the void reactivity coefficient positive which causes obvious design issues. RMWR and other development projects seek to use clever designs to overcome this problem. The "problematic" nature of aqueous wastes is often overstates by the anti nukes, remember that the PUREX plant at La Hague operates so well that even French Greenpeace have given up attacking it. FLUOREX requires only 10% of the material to go through the PUREX process and will thus reduce the aqueous waste content and provide a ready stream of uranium for re-enrichment without a separate conversion step.
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Post by Jonathan on Aug 30, 2013 18:05:38 GMT 9.5
Very poorly done, probably the worst I've seen on the topic. Conjecture and straw arguments abound. This is your "evidence"? Incredible.
A good reason I do not read this site anymore You actually think you can control all that radioactivity. Only in the BEST of circumstances can this be maintained TEMPORARILY - which CLEARLY cannot be counted on 100% of the time. The assumptions made in the linked articles are NOT IMMUTABLE FACTS which is what you need if you are going to create something as toxic as radioactivity and leave this crap lying around someday. You're assuming nothing will go wrong (forever) - the height of hubris and probably the most damning evidence of all against this insanity.
Suggest you read "The World Without Us" and the toxic legacy that will be left behind when we are gone .
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Post by edireland on Aug 30, 2013 21:06:37 GMT 9.5
A toxic legacy that there will be a handful of hectares of land where you cannot go digging? Or a few more hectares where it would be inadvisable to grow food?
If that is the extent of the toxic legacy left by our energy generation infrastructure I would think that it would be a glorious success for humanity.
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Post by rick123456 on Aug 31, 2013 3:06:43 GMT 9.5
edirland "(I once calculated you could buy the entirety of the UK the requisite 90 day course for a few tens of millions of dollars, could be stockpiled for use in case of a reactor accident)" Rick "But they have not done this and I do not think they will because of distribution and management cost, iodine to be supplied is scarce even"
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Post by rick123456 on Aug 31, 2013 3:31:47 GMT 9.5
cyrilr "The LNT model predicts that this guy should have died 4 times over from cancer from this radiation. Actually he didn't get any cancer. Funny. The results were the same for the other test subjects. What does this tell us about plutonium and about the LNT model?"
The study of plutonium used for treatment of Steve and others was done to see if there was a medical problem at a prepossessing plant that concentrates plutonium, some employees where having health problems. I have looked at many sites to see that the manufacturer was running the product through a cyclotron to make it pure with little or no daughter products, the daughter products are with plutonium except when processed in this method. They were not concerned with radiation entering the body by inhalation or digestion because of face masks and they were not eating any tainted food or water. They had another objective also, to see if this treatment could help with some medical problems, if so the cost per benefit may not of been acceptable, have not seen any thing concrete about this health effect just snips here and there on sites. They injected the study group with solutions containing small amounts of plutonium over a long period, they do not say what else was added or the amount of fluid. This is not close to the mix of radioactive isotopes that a reactor accident produces, the material after an accident has been many months decaying (decay has a way shorter half life of isotopes then in nature or less concentrated) and then goes critical or faster decay when a accident happens, this creates a cocktail of many isotopes which differ with each accident, checking for Cs-137 does not indicate what the mix is and is an assumption only. The mix from atomic bombs is well known but has far less number of isotopes and is the comparison to harm not what is not known. This was brought up early by a top scientist in Japan and was not answered. Plutonium breathed in goes through the body different then injected in blood, studies show damage to lungs and limp nodes, this is bypassed by injecting into blood, so again is not close to what happens around a nuclear accident or they would have written about this proving the safety of radioactive area. No one has commented on the formula I used to show that bio.. half life has no effect on the accumulation of radiation in a radioactive area, the study showed that the group did not excrete much of the radioactive material.
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Post by cyrilr on Aug 31, 2013 21:10:02 GMT 9.5
Rick, no one is commenting on your theories because you're so blatantly obviously clueless about basic concepts that people prefer to not talk to you. It's like trying to explain biology to a 2 year old child. Pointless.
Come back when you
1. have learned basic English 2. have learned basic concepts of biological half life versus radiological half life 3. are sober.
@ Jonathan. We have some 14000 reactor years, and hundreds of thousands of spent fuel storage years of experience to show that you are wrong. We can contain this, we are containing it, even despite numerous different approaches of numerous countries, some having been quite irresponsible with nuclear technology. The difficulty with spent fuel is in the first years after it comes out of the reactor, as it makes enough heat to damage whatever container it is in. Beyond that point it's simple, simple dry casks that are zero maintenance, we can contain this as long as we want. Every 50-100 years you lift out the assemblies and put it in a new cask. It is childisly easy. The average car garage could do this. It is not a technological challenge.
Regarding geological storage, google Oklo natural nuclear reactors and read up on this subject.
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Post by rick123456 on Sept 1, 2013 7:03:25 GMT 9.5
Cyrilr, This seems to tell it all. It takes time for the isotopes to be created that do the most damage.
The Steven study as was pointed out by others. Although the original estimates (and some later figures) concerning the activity of the injected solution were erroneous, modern research indicates that Stevens (who weighed 58 kilograms (130 lb))[2] was injected with 3.5 μCi 238Pu, and 0.046 μCi 239Pu, giving him an initial body burden of 3.546 μCi total activity.[8] The fact that he had the highly radioactive Pu-238 (produced in the 60-inch cyclotron at the Crocker Laboratory by deuteron bombardment of natural uranium)[8] contributed heavily to his long-term dose. Had only the long-lived Pu-239 been used as in similar experiments of the time, Stevens's lifetime dose would have been significantly smaller even with the same amount of activity. The short half-life of 87.7 years of Pu-238 means that a large amount of it would decay during its time inside a human body, especially when compared to the 24,100 year half-life of Pu-239. Pu-238 is about 270 times more radioactive per gram than Pu-239.[9]
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Post by Roger Clifton on Sept 2, 2013 17:05:22 GMT 9.5
This is something I found about it a while back, Hitachi are developing it along with their fast spectrum BWR. The primary reason that multiple recycle is problematic in LWRs is because the increasing plutonium fraction drives the void reactivity coefficient positive which causes obvious design issues. RMWR and other development projects seek to use clever designs to overcome this problem. So an excess of Pu239 makes a loss of coolant significant as a loss of absorber... Then surely the coolant could be designed less absorbtive, say, as HDO rather than H2O. Yet the web entry on RMWR says less water. I realise that fewer U fissions means fewer delayed neutrons and thus faster rise time. But it only needs to be longer than the designed feedback response. Perhaps that minimum U could come from a continuous conversion of Th232. Perhaps fast neutron spectra are possible in water cooled designs. That suggest the possibility of an initial plutonium charge, then burning all the higher actinides. Your reference to Hitachi's fast BWR is intriguing. Do you have a link? (The link above fails)
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Post by edireland on Sept 2, 2013 22:56:48 GMT 9.5
This is something I found about it a while back, Hitachi are developing it along with their fast spectrum BWR. The primary reason that multiple recycle is problematic in LWRs is because the increasing plutonium fraction drives the void reactivity coefficient positive which causes obvious design issues. RMWR and other development projects seek to use clever designs to overcome this problem. So an excess of Pu239 makes a loss of coolant significant as a loss of absorber... Then surely the coolant could be designed less absorbtive, say, as HDO rather than H2O. Yet the web entry on RMWR says less water. The RMWR is really a family of designs, although the Hitachi one seems far more technically promising. I have seen scattered references to using heavy water in a fairly conventional PWR primary loop however, but this appears to be a less heavily investigated path to the RMWR objective. It is not so much the 239Pu either, it appears to be many of the isotopes of Pu have this effect and since the proportion of plutonium in the fuel has to keep increasing with each recycle to make up for its reduced "grade" this becomes an issue. I realise that fewer U fissions means fewer delayed neutrons and thus faster rise time. But it only needs to be longer than the designed feedback response. Perhaps that minimum U could come from a continuous conversion of Th232. Perhaps fast neutron spectra are possible in water cooled designs. That suggest the possibility of an initial plutonium charge, then burning all the higher actinides. Your reference to Hitachi's fast BWR is intriguing. Do you have a link? (The link above fails) Hhhm, odd, that links work fine for me. Anyway, the Hitachi programme is known under a variety of names, RMWR (as a genericised thing) the RBWR (Resource Renewable BWR) and numerous other bits, but I think I have a core design link for a 330MWe design that shows the concept rather nicely. Here we go
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Post by seamus on Sept 5, 2013 5:17:06 GMT 9.5
Great series of articles, well done.
In part 4: "In almost all current examples, utility scale solar systems displace either wildlife or food production." Satellite solar power is one example I can think of, but by the time that makes financial sense, mining the raw materials and manufacturing the panels will all happen in space. In the meantime... liquid metal cooled, metallic-fueled fast reactors, of course.
Cancelling the IFR was as bad an idea as ending the Apollo program early. Sheesh!
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Post by jagdish on Sept 5, 2013 22:56:03 GMT 9.5
Russia, India and China are already building Sodium cooled fast reactors. The next steps in development of IFR can be 1. Pyro-processing of used fuel. 2. Metallic fuel for higher conversion/breeding ratio. or 3. Fluid fuel (MSR) core for synergy with pyro-processing. Success in these countries will pave the way for acceptance elsewhere.
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Post by edireland on Sept 6, 2013 0:06:23 GMT 9.5
India has its own energy-security reasons for pursuing it, the Russian Fast Reactor programme appears to be going nowhere fast and the Chinese are just throwing money at everything that moves.
I don't think LMFBRs are going to be a major player. Especially if seawater uranium extraction works.
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Post by jagdish on Sept 6, 2013 8:57:18 GMT 9.5
Fast reactors are an essential and productive part of IFR. Recycling via pyro-processing is the rest of it. China is much more energy hungry than India. Russian energy future is fast reactors. Asia minus Japan and plus Russia is where the nuclear action currently is.
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