I hear that these things are great: meltdown proof in the case of a loss-of-coolant accident, commoditizable (to coin a word) reactor vessels, ability to throttle the power, pebbles that act as their own storage vessels, don’t need a secondary coolant loop, etc. Where are they? I hear that South Africa is working on them and that China has some research reactors working and that Idaho National Lab has a research reactor, but I haven’t heard any news about any of them lately. What are the roadblocks in the way of this technology?
From what I recall from this article in WIRED, from 2004 (it was an interesting enough topic to remember!) is that in other countries the roadblock is money and in the US the roadblock is the popular fear of nuclear anything.
Even in 2004, though, nothing was really promised until the end of the decade anyway, so it seems like it could just be a slow process rather than a stalled one.
Toshiba has a major research program with these, but I don’t believe they’re very scalable. In the US at least, you’re probably going to have a much easier time applying for permits for one 10GW plant than 20 500MW plants, politics being what they are.
Uranium prices are rising too, but building breeder reactors in the US is still a political non-starter.
Well, PBMRs are designed so that one control station can control multiple reactors. I am not familiar with the regulatory process, but I would think that you could get a permit for several reactors at once. The vessels are designed so that they can be prefabricated and certified independently, so that may help streamline the process. Also, fuel is a very small part of reactor operation cost. I have heard that doubling the fuel cost would only add something like 5% to the operational costs of the plant. BTW, breeder reactors are an economic non-starter as well.
I think I have some more info. China and South Africa are both working on getting these up and running. Prototypes in the US as well for research. Germany had one up but they violated the premise of the whole deal by trying to build too large a single block house (yes its more efficient but it then negates the inherent safety effects of doppler broadening). Sure enough they damaged one of the ‘pebbles’, started a fire and then shut the whole thing down.
I dont get why there isnt real excitment with these designs. Use a modular design, keep the volume below the meltdown thresehold (you need a specific amount of fuel or greater to meltdown), use helium as your heat transfer medium through a couple of big GE turbines, and then use the waste heat to produce Hydrogen. No steam is used, no waste heat into the rivers, no cooling towers, and no high pressure steam.
Fast reactors run at the perfect temperature for the waste heat to be used to convert water to Hydrogen and Oxygen (cracking). Dump the ‘waste’ hydrogen into the transportation sector to promote hydrogen cars and then if you really want to get interesting dump the remaining waste heat after the cracking process into a solar tower structure to generate even more energy.
The downside is the waste generated of course and in the US Yucca Mountain would need to be mandated to open to receive it. The interesting thing to me is that the fuel in a pebble bed reactor is already in inherently stable form. Additionally the waste generated should be about the same amount of radioactive material that is sent up the stack and out into the atmosphere by a coal plant (average coal plant pushes about 3 ton or Uranium up and out the stack in a year).
The only arguement against, besides the waste issue I have seen is hystrical shrieking on some site driven by an anti three mile island group complaining that pebble bed reactors dont have containment buildings. This is about the same level of sophistication as screaming that airplanes dont have enough Helium in them to keep them in the air.
Sorry for the long post. I’d really like to get this discussion going. I am actually considering pursuing a Master’s program on this subject because I think this technology is real. Please hit me with real or percieved issues on this. I want to have the dialouge on this topic to find out where the hole in this technology is.
I love the idea as well. However, like most “alternative” energy production ideas, it suffers from the fact that oil is cheaper to produce. The other problem is that most of the alternatives are relatively complex and hard to develop cost estimates. Wind has the unusual advantage of being quite simple-no fuel inputs no waste outputs. Build them and the associated power lines and be done. Easy to develop budgets. Hence, one of the few alternative sources that are actually are going someplace.
The problems are that not every region is windy enough to make it worthwhile, people don’t like their view spoiled by massive turbines everywhere (though I think they look futuristic and cool), and there are always the people who complain about how many birds are killed by the things (one seems to be too many).
Geothermal is a more extreme example: Cleaner and less intrusive than wind, but extremely geographically limited. I’m sure there are parts of Yellowstone that could support a small geothermal project without damaging most of the park but the political ramifications would make every hair on your head stand up like quills on the fretful porpentine.
Depends on whether you include hot dry rock geothermal - it’s probably at an even earlier stage of feasibility than pebble-beds, but if they manage to commercialise it it could be a game-changer.
I’ve been wondering lately how much of the startup costs on any sort of Nuclear Reactor in the US are sucked up in legal costs and fighting against NIMBY groups. Anyone know, or have any idea?
Can the pebbles fail because of internal gas pressure from generated radon? I understand that one of the layers is porous to absorb generated gas. Is the pressure build-up too small to be of any concern?
Besides NIMBY and the regulatory process, what prevents the reactors from being built? There must be technological hurdles left to overcome. What is it that the research reactors are researching?
Nobody knows what the actual legal start up costs are currently in the US because they havent seriously tried to build a commercial plant since the early 70’s. Recently some legislation was run through to try and balance the need for real risk assessments against organizations who use the legal system to stall projects they dont like. I think about 10% is what is estimated although with the legal beating coal plants are taking that is probably low.
Oil is no doubt in some areas cheaper to produce but I think the US has gone away from oil fired plants to generate electricity. PBMRs are set up to generate electricity and at a long term cost per megawatt hour that is slightly more expensive than coal but I beleive is actually cheaper than the cogen plants that are currently going up. Cogen plants are cheaper to get online but the fuel costs over a 30 year life come back to bite you.
What I was trying to push was a site where you got your electricity for the grid (and nuclear can be used as your baseload, which solar and wind can’t because of reliablity issues) from a PBMR and then with the waste heat you get Hydrogen for the ‘Hydrogen economy’. Two for one. Then dump the residual heat into a solar tower. Three for one.
I am a year away from the thermodynamics and fluids classes I need to try and work through the math on how much heat a plant puts out but wondered what stupid mistake I am making.
Also a coupple more things about wind (I live in MT and they are big on them up here right now). Our sites up here dont produce any power in winds less than 10 mph or greater than 28 mph so its a specific band. Additionaly power losses in transmission make alot of sites difficult economicly. North Dakota is great for wind just difficult to get it to a large population.
I use geothermal to heat my house and love it. I have a heat pump and a closed loop system that has 3200 feet of pipe buried underground. In the winter we take heat from the soil (nothing special about it except little rock made the digging easier.) in the summer we dump heat back in. Heating and airconditioning for the operating cost of a fan and a small circulating pump.
One of the problems of PBMRs is that its not familiar tech. I believe the Navy and Atomic Energy Comission in the US pushed light water reactors for civilian use because it parralleled the Navy program for its ships. Economies of scale…