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Distributed "Nuclear Batteries" the New Infrastructure Answer?
thepacketmaster writes "The Star reports about a new power generation model using smaller distributed power generators located closer to the consumer. This saves money on power generation lines and creates an infrastructure that can be more easily expanded with smaller incremental steps, compared to bigger centralized power generation projects. The generators in line for this are green sources, but Hyperion Power Generation, NuScale, Adams Atomic Engines (and some other companies) are offering small nuclear reactors to plug into this type of infrastructure. The generator from Hyperion is about the size of a garden shed, and uses older technology that is not capable of creating nuclear warheads, and supposedly self-regulating so it won't go critical. They envision burying reactors near the consumers for 5-10 years, digging them back up and recycling them. Since they are so low maintenance and self-contained, they are calling them nuclear batteries."
The liquid metal reactor takes advantage of the physical properties of a fissile metal hydride, such as uranium hydride, which serves as a combination fuel and moderator. The invention is self-stabilizing and requires no moving mechanical components to control nuclear criticality. In contrast with customary designs, the control of the nuclear activity is achieved through the temperature driven mobility of the hydrogen isotope contained in the hydride. If the core temperature increases above a set point, the hydrogen isotope dissociates from the hydride and escapes out of the core, the moderation drops and the power production decreases. If the temperature drops, the hydrogen isotope is again associated by the fissile metal hydride and the process is reversed. The chemical isotope splits chemically when it gets too hot. Just like water boils and turns into steam, you can design the water system to not exceed the boiling point of water. You would have to keep the water under pressure to force higher temperatures.
The safety systems will be similar but the reactor cores are different between the Triga (fuel rods in a pool type reactor) and the Hyperion Power Generation Uranium Hydride (liquid metal) reactor.
If you were going to blow it up, it would take a lot of explosives -like blowing up a 15-20 ton buried bank vault. A lot of explosives to penetrate the concrete cask and then more to blow through however many feet of dirt it is buried under.
It would not add much to the cost to have sensors and digital video camera security to these things. So extreme tunneling, attempts to move it or blow it up should be easily detectable and action taken.
For the amount of effort and explosives it would take then just take those explosives and add radioactive material (available in mines and in less secure facilities and sources) and then put your dirty bomb anywhere. Thus there is no incremental risk.
The nuclear material is tougher to turn into nuclear bombs than using raw uranium, which a terrorist could get from natural sources (mines etc...). Again no incremental risk (we are adding no new risk as there is an easier existing path).
For getting oil from oil shale this system can supply heat instead of natural gas. Hyperion also offers a 70% reduction in operating costs (based on costs for field-generation of steam in oil-shale recovery operations), from $11 per million BTU for natural gas to $3 per million BTU for Hyperion. Over five years, a single Hyperion reactor can save $2 billion in operating costs in a heavy oil field. A lot of the initial one hundred orders are from oil and gas companies.
A single truck can deliver the HPM heat source to a site. The device is supposed to be able to produce 70 MW of thermal energy for 5 years. That means that the truck will be delivering about 10.5 trillion BTU's to the site. Natural gas costs about $7 per million BTU which would would cost $73 million.
It would be better to compare the HPM to diesel fuel, which currently costs about 2 times as much per unit of useful heat as natural gas and still requires some form of delivery for remote locations. In some places, fuel transportation costs are two or three times as much as the cost of the fuel from the central supply points.
In certain very difficult terrains, or in places where there are people who like to shoot at tankers, delivery costs can be 100 times as much as the basic cost of the fuel.
Initially these units will be in remote areas near oil sand projects and they will not be directly under people's houses. Do people live directly over power transformers or oil refineries ? The first few thousand can be placed on the site of existing nuclear and coal plants which have a few square miles of space. Even if there eventually there was one for every twenty thousand or ten thousand homes, they would be situated in some industrial zoned area. For eastern europe and island developments, the units will be sited several hundred meters from where people
Solar takes a lot of space and puts out a lot less power. It's also costlier. And the process of manufacturing solar panels is horrible for the environment.
Nuclear power is, believe it or not, the cleanest technology we have available, even if you consider the highly radioactive waste and the (typically minute) risk of meltdown.
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There are two kinds of nuclear bomb-- Uranium and Plutonium. In order to get a Uranium bomb, you have to have highly enriched Uranium (a high U-235 to U-238 ratio). These reactors don't have anywhere near the U-235 ratio for that. The second option is Plutonium which is not a naturally-occurring substance. It is the by-product of some kinds of fission, and can be made in a specially designed nuclear reactor. These aren't those kinds of reactors, so you're not going to get enough Plutonium to be useful in weapons development.
Thus, one of these things wouldn't be much of a head-start over just mining some Uranium ore.
E pluribus unum
to be fair there would be virtually no waste to worry about if reprocessing were allowed.
Our current problem is that spent fuel still contains much fissle material, and reprocessing fuel rods to get the material out is disallowed by the DOE.
If you reprocessed the fuel to make new fuel, and were left with only the low level waste then the radiation hazard would be fairly comparable with coal ash.
-nB
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The irony is that a Coal Plant is actually MORE radioactive than a Nuclear Plant!!
http://www.sciam.com/article.cfm?id=coal-ash-is-more-radioactive-than-nuclear-waste
Hint: It in the ashes and it affect 1 mile around it. Don't eat stuff from your garden!
Obama's legacy: (N)othing (S)ecure (A)nywhere and (T)error (S)imulation (A)dministration
That's exactly right, but people prefer letting the papers think for them. In a nutshell: If the thing didn't go critical, it would not be a viable power source. Criticality is the condition where, on average, each fission begets one further fission--this is how a constant power level is maintained. Further, supercriticality corresponds to increasing power output, and subcriticality to decreasing output. All of these conditions are necessary for the reactor to respond to changing power demands, and none of them is inherently bad.
One reactor design is made to prevent critical events from forming. Toshiba's 4S reactor. The reactor uses a neutron reflector to bounce neutrons back at the reactor core, heating it up as the reflector moves up and down. The faster the reflector moves, the more energy is produced. Something breaks, meeting SCRAM conditions, the reflector simply stops moving, the reactions stop, moving back down to relative background conditions. The design is modular, the core is sealed at the factory and moved to the site in a single piece containment vessel. Being sodium cooled poses risks, but is manageable.
This design will provide 10 MW @ 75% capacity for 20-30 years.
First rule of holes; When in one, stop digging.
Chernobyl... yes, big disaster. 3 mile island? Literally not an issue... the safety measures contained the problem. Study after study has not shown any increase in cancer or teratogenic effects. Basically you'd get a lower dose of radiation living near 3 mile island than you would living near a coal fired power plant.
I'll never make that mistake again, reading the experts' opinions. - Feynman
Also Chernobyl was due to bad design and poor saftey and maintainence procedures.
Nuke is not 100% safe, but you could also get crushed under a solar panel or more-likely have the chemicals and other pollutants used in making the panel poison you.
Nuke can be safe and clean as well as relatively cheep with proper care and maintenance. It isn't a gift from Maya the Earth Goddess but then again it isn't a scheme by some villain from Captain Planet either.
At TMI about half the core melted and formed a puddle at the bottom of the pressure vessel. Even though they eventually pulled their heads out of their asses and saved the day, that is most definitely an "issue".
Disclaimer: That's not to say that we haven't learned anything in the 40 years since TMI was designed. I find it absurd that we stopped making nuke plants. We should be building shiny new safe ones so that we can decommission all the old time bombs.
The "saving the day" was way after the meltdown. The big concern was the hydrogen bubble formed in the reactor vessel by the reaction between steam and the much hotter than normal Zircaloy fuel cladding. The problem was the risk of the hydrogen causing an explosion that would rupture the vessel.
The meltdown was a concern from the regard of waste handling (as you can't simply pull the fuel cells out of the core like for a normal refueling) and due to the risk of destroying the first layer of containment (the reactor vessel). Even if the melting core material had ruptured the vessel however, that's why reactors in Western nations have a containment vessel to hold the contaminated material (and keep radiation levels outside the containment vessel at background levels).
Keep in mind that TMI-2 was scrammed the entire time the core was melting down -- this was not a runaway nuclear reaction, this was a loss of core cooling (a nuclear core will generate "decay heat" for some time after it is shutdown). So a meltdown is not a concern for radiation generation per se but rather for nuclear plant integrity.
Are nuclear meltdowns an issue? Of course they are -- they wreck a tremendously expensive nuclear core and the cleanup is it itself even more expensive than normal. But it is nowhere near the same league as Chernobyl (which violently blew up due to managing to achieve "prompt criticality", which is the criticality you want to avoid).
Very true but perhaps understated. Even the poor procedures at Chernobyl were ignored. From what I have seen, the operators in the space of an hour managed to do practically every DON'T in their procedural manual, including overriding the safety systems to withdraw more control rods than was permitted under any circumstance.
That coupled with an inherently unsafe design and wildly fluctuating power output (due also to operator error) perfectly set the reactor up for a thermal runaway.
With appropriate fuel reprocessing, nuclear has the potential for the LEAST environmental impact of any power source including wind (kills birds, spoils view), solar (takes up large land areas), and hydro (kills fish, prevents return to spawning grounds).
I remember reading that it takes more energy to build a Solar power system than that system will deliver in it's expected lifespan. Is this true?
No.
To elaborate: picture a 200W solar panel, it weighs about 30lbs and has a lifetime of 20 years or more. In those 20 years, if you average 8 hours a day of full output, that's 1.6kWh per day, or over 11 Megawatt hours. A moderately sized factory might consume 11 megawatts, but if it's that big, it had better be turning out more than 1 solar panel per hour.