They did blow up two planet-sized Death Stars, killed millions maybe billions of people, contractors, construction workers, canteen staff, janitors etc. They gave medals to the grinning yahoos that did it.
I live in the centre of a city with the best public bus service in the nation, operating at a profit with regular clean modern buses, express services to the airport, park-and-rides, good handicapped access, night bus services etc.
Despite this the big city centre employers like the financial services companies, healthcare, TV stations etc. all run their own shuttle bus operations as the public buses don't necessarily go from one office to another, although a few bus routes actually go into company campuses to pick up and drop off passengers at the office front door as well as passing through the business parks on the city outskirts.
Nobody's built a liquid salt thorium breeder (Th-232 -> U-233) reactor yet, and licencing the design in the West could take decades -- even conventional PWRs can take more than ten years from proposal to first concrete and they're proven designs, steam-boiler simple with no 700 deg C liquid fuel to cope with. Even according to the Powerpoint Rangers who are pushing LFTR as the Ultimate Fix For Everything Nuclear waste actinide destruction requires an enormous fast neutron flux only available by fissioning lots of U-235 and Pu-239 in the liquid salt stream and that will produce significant amounts of fission product waste, hopefully not as fast as it burns existing waste actinides if it is tweaked for that role -- the breeding process needs a lot of neutrons too and there may not be enough to go around to do both at the same time.
The liquid-salt thorium breeder system involves very high temperatures and radioisotope chemistry interacting with the piping over decades of use, not to mention the continuous reprocessing plant powered by handwavium which produces its own intensely radioactive waste stream. The track record of sodium-cooled plutonium breeders where the ceramic fuel doesn't move and the engineering and chemistry is better understood isn't too good -- lots of pipe cracks, coolant leaks, fires etc. over the years. LFTR makes a nice graduate student presentation at TED though, great slides with "and then a miracle occurs" in 8-point Comic Sans at the bottom.
The IFR and its cousins are less fanciful prospects, indeed Russia and China are actively (as in bending metal and pouring concrete) working on fast-spectrum reactors like the BN-800 and the proposed CDFR which will have the capability to burn actinides as part of their function but they too will produce lots of fresh fission products. The current fast-spectrum designs like the smaller BN-350 (operating in Russia since 1980) also generate electricity and breed plutonium from U-238 depending on their operational configuration.
Vitrification (what you Yanks call "glassification") is carried out to stabilise the waste from reprocessed fuel The US doesn't reprocess fuel on any sort of scale although it may process defence-related nuclear waste.
Typically a tonne of spent fuel will contain a couple of kilogrammes of actual waste fission products, the rest is nearly all uranium and a small amount of plutonium. Reprocessing and vitrification vastly reduces the physical volume of waste but it doesn't reduce the radioactivity emitted by it since uranium and plutonium are quite long-lived, it's the shorter-halflife waste isotopes that produce nearly all of the detectable radiation and residual heat in spent fuel.
The Izumo is a replacement for the existing smaller Japanese helicopter carriers and they plan to build a second one. Some defence-oriented website put up a scale comparison picture -- the Izumo is about the same size as the IJN fleet carriers like the Akagi that attacked Pearl Harbor in 1941. It's still significantly smaller than the USMC's Tarawa LHD carriers and the forthcoming America class replacements for the Tarawas are even bigger targets^W.
I can't actually think of a notable writer from Glasgow -- Alasdair Gray perhaps? Google Google wikiwiki yup, born in Riddrie and still lives in Glasgow. That's it. The Scottish Socialist Vanguard Science Fiction Writers Party is all on the east coast (Iain M. Banks (RIP), Ken McLeod, Charlie Stross, Hannu Rajaniemi etc.)
Capaldi's Glaswegian, not Boston Irish. Don't know why you went with an American dialect rather than something fae Glesca.
Rough translation into Barras Glaswegian -- "Haw, d'ye fuckin' ken who yer fuckin' dealin' way here? Well Ah'm th'fuckin' Doaktur ye bastardin' wee alien ba'heid, noo get fuckin' oota my fuckin' sight afore ah fuckin' stick th' fuckin' heid in ye!"
Ontario has brought some mothballed nuclear reactors back into service in order to shut down their existing coal-burning generating stations, with the last one due to close next year. There's a single gas-fired converted coal-plant and they're planning to develop a biomass fuel chain for one of the other plants. They do have a lot of hydro power though, typically about 6GW generating capacity at any given time. The nuclear fleet provides up to 6.6GW depending on the number of reactors running at any given time. Here's the real-time generating information for the assorted facilities Ontario Power run -- basically the nukes run flat out, the hydro generating sets throttle up and down and the thermal (mainly gas) power stations fill in the cracks.
The current designs of nuclear plants being built around the world have an initial design life of 60 years, not "a couple of decades". They may well go on operating for a century depending on maintenance, fuel costs etc.
The existing fleet of Gen II reactors built in the 70s and 80s are reaching the end of their initial licencing period of 40 years but after inspection and some upgrading here and there quite a few of them are getting a licence extension of ten years with the expectation that they could well get another 10-year operating extension on top of that.
I'd do a point-by-point refutation of your arguments but I can't be buggered. I'll just say if you think that piping a few hundred tonnes of incredibly hot and mind-bogglingly radioactive sludge through a moderating core and a continuous reprocessing plant for decades on end is not complex compared to a PWR where water is sprayed onto solid fuel rods in a pressure vessel then I don't know which planet you're living on.
If you can get past the PowerPoint Rangers and the graduate student "and then a miracle occurs!" presentations about MSRs and thorium breeders into the nitty-gritty of producing significant amounts of power from nuclear energy then the MSR concept falls down in a lot of aspects. It might be the greatest thing since sliced bread after a lot of expensive debugging but right now it's a solution (so to speak) in desperate search of a problem that doesn't really exist.
It's kind of difficult to think back that far but in the 70s space launches were complicated things, not run-of-the-mill operations like today. One of the constraints that resulted in the Shuttle design was the necessity to launch the crew and payload in one shot. The idea of launching two or three individual payloads and crew capsules within a few days of each other and have them make rendezvous in orbit was beyond the capability of anyone at the time. The Shuttle was basically a variant of the one-shot Apollo-Saturn stack for that reason.
When the Shuttle did fly it provided a shirt-sleeve environment for up to seven crew for up to 28 days (although they never flew that long), a large flexible payload bay and about 20 tonnes or so of lift capability, two-person spacewalk support with the ability to carry out multiple missions, quite a lot of delta-vee to move around or to change orbits, a toilet and a shower (sheer luxury for the spam-in-a-can capsule pilots of the previous generation and not something the SpaceX Dragon capsule or the Boeing offering is going to be fitted with) and it came back to land, not requiring an aircraft carrier group to go pick the crew up out of the Pacific 135 times.
If the Shuttle hadn't been as reusable as it was then I suspect the operating budget of whatever replaced it would have been trimmed back gradually and the end of US manned spaceflight in US-launched vehicles would have come a lot sooner and the ISS would never have been built, or at least not on the current scale.
I've been mulling over an idea about using spare lift capacity on launchers to implement this tank-farm idea, but not for hypergolic fuels as would be needed by landers, manned probes etc. Instead of carrying toy cubesats and such, if spare mass is available on a launcher use that capacity to loft standard-sized tanks of liquid argon or preferably xenon into LEO. This would be used as reaction mass in ion drive engines, already well-proven in various space applications.
After separating from the main launcher bus in LEO the liquid gas tank would be collected by a robot tug powered by ion drive and solar panels and taken to a tank farm in a higher orbit where atmospheric drag won't cause the tanks to re-enter. From there other ion drive-powered tugs fuelled by the liquid gas could take reaction mass up to GEO to top up some of the satellites there that are already using ion thrusters for stationkeeping. In addition any deep space probes that use ion engines can get fuelled up in orbit rather than having to carry their own reaction mass all the way up from the ground.
The tugs don't need to be very powerful, they're in no hurry as any vehicle they supply isn't going anywhere and can usually afford to wait for a few days or weeks to get fuelled up. It's not much use for manned flight and the like although it might help to power a pipeline for a manned Mars mission, helping to delivering robot supply vessels to Mars orbit in the same way Progress, ATV and the Dragon capsule supply materials to the ISS.
A surprisingly large amount of stuff sent into low earth orbit and even geosynchronous orbit consists of fuel and oxidiser. The Shuttle launched with over 14 tonnes of manoeuvering fuel and oxidiser on board for the OMS and RCS motors. That's 14 tonnes that couldn't be dedicated to payload, food, water etc. Similarly a geosynchrononous satellite weighing 6 tonnes will be carrying two or three tones of fuel and oxidiser so it can maneuver into its final orbit and allow it to maintain station for a decade or more. Some GEO birds have been decommissioned when they nearly ran out of fuel, not because they broke down or became obsolete.
Using a slingshot or other brute-force technique to put tanks of fuel and oxidiser into orbit cheaply could well be worthwhile; robot tugs could collect them into a tank farm of some kind in a higher orbit and then deliver fuel and oxidiser to various vehicles as needed rather than them having to lift their entire fuel and oxidiser loads along with delicate electronics, structural components for Mars landers, fleshy meatbags etc.
I think a long technical discussion of MSRs and thorium-breeders is outside the remit of the poo-flinging and "...xxx YOU!" jokes that normally goes on in typical Slashdot threads.
The base line is that any technology used to generate electricity has to work at a ticket price people are willing to pay with operating effects on the world they are willing to accept. Right now coal is king even though it kills thousands of miners each year extracting it, produces unconstrained toxic waste by the megatonne and is poisoning the atmosphere. The only upside is that coal is cheap and plentiful and there's lots more where it came from so it is used to generate over 40% of the world's electricity. Gas is less toxic but still loads the atmosphere with CO2, right now it's cheap if less plentiful than coal and doesn't kill lots of people extracting it. Conventional nuclear is about as cheap as coal per kWh of generation and doesn't emit CO2 but it has a number of perceived downsides most of which the nuclear industry will tell you have been fixed or can be fixed.
MSR technology is not going to solve that "perceived downsides" problem that the nuclear power industry labours under around the world -- it still involves fissioning uranium even if it's bred up from thorium, it still involves fission byproduct waste, it's still going to need large amounts of capital up-front to build commercial plants and cover all the regulatory costs of getting them built. MSR designs are not going to get a pass because it's much more complex than a steam-engine-simple PWR but THEORETICALLY safer. An MSR that produces commercial electricity at three or four times the cost per kWh of other baseload generators is not going to get funded in the first place, basically.
India is not a signatory to the Non-Proliferation Treaty (NPT), like North Korea, Pakistan and a few other countries who want to possess and develop nuclear weapons outside the treaty's limitations. As such other nuclear-capable nations are not permitted to supply it with nuclear materials and technology. This ban should include selling them uranium, fuel elements and other raw materials as well as engineering equipment, design expertise etc. In practice the US and some other countries skirt the treaty and help the Indians out as long as they promise not to divert the materials and equipment into their nuclear weapons development programmes.
The thorium-fuelled PWRs India is planning are clumsy affairs, effectively breeding and burning their fuel at the same time, producing less power per kiltonne of concrete and steel than a modern PWR. The fuel cycle is a lot more complex with inputs of medium-enriched uranium (probably from their military reactor fuelling programmes and weapons development) and scarcer plutonium, again derived from their military reactors. This is going to be significantly more expensive than conventional PWRs would be even if they bought in yellowcake and established their own fuel element manufacturing capability as other uranium-poor countries like China are doing.
Either they continue to keep the IAEA inspectors out of their military nuclear facilities by remaining outside the NPT umbrella or they pay for it by spending more to keep this jackleg fuel cycle running due to an inability to buy uranium on the open market at firesale prices. It's their choice.
I have a car but I live in a city centre, it takes me at least half an hour to get to the outskirts through a maze of twisty little roads. After that it's about 40 minutes by motorway then another half-hour to get to the city-centre store where there's no local parking as it's in a pedestrian shopping street so I would have to park some distance away and walk. Time at the store, wait wait wait, then reverse the process. Four or five hours at least and it has to be done during the store's opening hours so I can't do this in the evening after work. That's a day taken up pretty much.
It's actually easier and cheaper for me to take the train if I need to go there, assuming I'm OK carrying whatever it is needs fixing - a 30" Thunderbolt display is not a small bundle to tuck under one arm.
The utilities are required by US law to hand over control of spent fuel to the government and pay for its disposal. They've done that, the government generally hasn't taken it away as they said they would and the only major attempt to build a spent fuel depository at Yucca Mountain turned into a congressional pork project and then was cancelled after about $9 billion was spent building it.
Uranium is cheap because there's a lot of it about. The warheads-into-fuel projects currently operating only provide a few tonnes of fuel per year for the world market -- the entire world's stockpile of nukes amounting to about 25,000 warheads in the late 1960s contained maybe 200 tonnes of highly-enriched uranium and Pu-239 in total and a single 1GW PWR will burn a couple of tonnes of U-235 or Pu-239 each year. I did a rough calculation once and figured the entire American stockpile of nuclear weapons could provide the nation's electricity demands for about two weeks, no more.
The insurance thing is a lie. The utilities are required to carry large amounts of liability insurance, up to about $10 billion or so under the Price-Anderson Act. After that the government is the insurer of last resort in the same way they're spending fifty billion dollars to rebuild in New York and Jersey after Hurricane Sandy hit, overwhelming the flood and disaster insurance market there. Ditto for Katrina and New Orleans etc. The second-worst nuclear power accident in US history at TMI never required asking the US government for funds despite the operators spending tens of millions dealing with lawsuits. The cleanup operation is only costing a few hundred million bucks total. Before you ask the worst accident was the SL-1 reactor incident in the 1960s as there were three fatalities unlike TMI where there were no casualties at all.
As for thorium, again I have to explain that Th-232 is not a nuclear fuel. It can be bred into U-233 by exposing it to a neutron flux, most easily by putting it into moderated proximity to real nuclear fuel like U-235 and Pu-239/240 at which point via spontaneous and induced fission the U-233 produced will release energy with all the benefits and downsides of its kissing cousin isotope U-235. Th-232 by itself just sits there.
The liquid-fluorine thorium reactor so beloved of the Powerpoint Rangers is a BREEDER reactor, not something they ever emphasise in their TED Talks because breeders have a bad rep in the nuclear world, expensive and uneconomic hangar queens even when they've not broken down or leaked their coolant/moderator over the floor and/or caught fire. Given that MSR designs are even more complicated than "conventional" breeders I'm not surprised they don't emphasise the B-word.
You want nasty? Imagine going deep underground and digging coal out of wet gassy seams, transporting it hundreds of miles and burning it in power stations and dumping the fossil carbon into the atmosphere as CO2. Well, actually humanity does that today -- 7.6 billion tonnes of coal or thereabouts were produced and burnt in 2011 alone to generate less than 40% of the world's electricity demand.
In comparison the world's fleet of about 400 power reactors, generating about 20% of the electricity used in the world consume less than 50,000 tonnes of uranium a year. The extra cost of processing and enriching the fuel is a pittance given the high energy density per gram of fuel -- the biggest costs for nuclear power stations are the operations (salaries, inspections, maintenance, landscaping etc.) and paying the loans that built the plant in the first place. Fuel costs even after enrichment etc. is about 0.7 cents/kWh.
The "seed" for thorium reactors is actually U-235 and Pu-239/240, U-233 is what thorium (Th-232) has to be "bred" into by absorbing a neutron before it can create recoverable energy by fissioning from a neutron impact. After that it's just like a regular reactor, fission products, decay heat, and all.
There is no engineering knowledge about how steel alloys cope with direct contact of highly radioactive molten salts at 700 deg C for decades on end. It could be very expensive to find out the hard way if the alloys chosen don't stand up very well to the conditions. We know a lot about how reactor vessels, pumps and piping exposed to high-pressure steam at 300 deg C and limited neutron bombardment for decades on end perform because there are hundreds of reactors out there as operating testbeds, and the knowledge base says they do pretty well at it.
Neutron embrittlement does happen, as does some activation by fission or more commonly neutron capture but the major structure in a PWR, the reactor vessel itself is massively overengineered for decades of expected troublefree operation. It's a giant pressure-cooker with no moving parts, all it has to to is endure the heat and pressure and it never comes in contact with hot fuel, only water and steam. It certainly receives a lot of neutron flux but the walls of the vessel are some distance from the core and the internal structures which carry the fuel rods, the water injectors, control rods etc. Compare that to the amount of neutron flux the piping, heat exchangers etc. in a LFTR will be exposed to as they are in direct contact with the highly radioactive fuel and decay products for decades on end and at high temperatures. Decommissioning that piping at end-of-life will be a radiological nightmare.
As for byproducts I hope you realise that the heat energy from thorium fuel in LFTRs and even the Indian MOX PWRs actually comes from fissioning U-233 and that fission process results in the same isotopes that are produced in a regular U-235-fuelled PWR, if in slightly different percentages. The awkward medium-life products still have to be dealt with like Cs-137 (half-life of 30 years) and its close friends.
Power reactors didn't produce weapons-grade plutonium anyway. PWRs and such salt the Pu-239 they breed from U-238 with Pu-240 when it captures another neutron and that screws up implosion weapon designs to the point where they don't work right if at all. There were some dual-use reactor designs like the British Magnox and the Russian RMBK-4 that could be operated to breed purer forms of Pu-239 but by the time they came on-line in the 60s the major Powers had made all the Pu-239 (a few hundred tonnes in total) they'd ever need from dedicated short-cycle breeder reactors in places like Hanford and Windscale. You don't need reactors at all to build U-235 weapons of course, just enrichment facilities.
The good news is that molten-salt thorium reactors work by breeding Th-232 into U-233 and that can be easily extracted and turned into quite usable nuclear weapons (the US fired off a couple of test U-233 shots in the 50s, I don't know if the Soviets ever did). Given that a molten-salt thorium reactor positively requires a reprocessing plant which can extract the U-233 to keep it running is just another bonus for any wannabe new entrants to the nuclear weapons club assuming molten-salt thorium ever gets productionised.
Molten-salt thorium reactors are currently in the Powerpoint stage of development with a lot of handwaving over parts of the design involving really problematic engineering and logistical hiccups. For example the highly radioactive molten-salt fuel has to circulate at about 700 deg C though piping, pumps and heat exchangers -- most steel alloys lose half their strength at those sorts of temperatures and if a joint goes bad then you can expect a disaster in the containment or worse still in the steam generating plant. See the various metallic sodium leaks the breeder builders have suffered over the years for a worked example. The fuel stream has to be continually reprocessed to remove fission products that would poison the reaction by absorbing neutrons, not something the 1960s experimental molten-salt test reactor ever attempted to do. These reprocessing stacks will be highly radioactive for centuries or even millenia, assuming they last long enough for the reactor to run for more than a couple of years before breaking down and they will be horrendously expensive to decommission. Etc. Etc.
In comparison the fuel in a PWR or other power reactor is a solid ceramic pellet (melting point about 2200 deg C) that sits in a zirconium fuel rod jacket and doesn't go anywhere unless a disaster happens. When the refuelling operation happens the spent fuel rod assemblies are taken away and stored in a pool for a few years to cool down and let the decay heat from the fission products fall to a level where storage in air will suffice without the rods overheating. After that they can be buried or, depending on circumstances, reprocessed to reduce the volume of real waste to a few percent of the original fuel pellets and the unspent fuel recycled. And that's it, no Powerpoint Rangers, just 60 years and more of actual real-world reactor operations experience.
Some of the richest uranium deposits known are in northern Canada, in locations so remote they'd have to fly the yellowcake (uranium oxide in the form of U3O8) out in cargo planes. Today the spot price (25th July 2013) for yellowcake is $40 per lb. which makes it uneconomic to work that ore body given the logistics costs involved. If the price of yellowcake tripled then maybe it would start to be worthwhile opening up those orebodies. That tripling of the raw material price would only increase the price of nuclear-generated electricity by about 1.5 cents per kWh though because the fuel is still ridiculously cheap and a minor part of the total cost of nuclear electricity.
Long time back before WWII, nobody was really interested in uranium, it had little or no industrial uses. After WWII everybody started looking for it but it was thought at that time it was rare hence the early interest in thorium, breeder reactors etc. It turned out that it was actually quite a common substance with lots of easy-to-mine ore bodies in places all over the world. We're still working on the easiest to extract sources of uranium because they're cheap. As they run out we'll dig up more expensive ores, lesser grades requiring more digging and processing and the price will rise.
The wonderful thing is that uranium is so compact a source of energy that we don't need to dig up a lot of ore to keep the lights on, not compared to coal or oil or gas. The US' entire electricity demand could be met by a couple of million tonnes of uranium ore each year, without reprocessing spent fuel -- if that was done (at a price) a few hundred thousand tonnes of ore would suffice. In comparison it would take about 4 billion tonnes of coal each year to do the same job.
The bottom line price for uranium is extraction from seawater -- Japanese experiments suggest that would cost about $300 per kilo of uranium metal although nobody's bothered to build a pilot extraction plant because, guess what, uranium is so cheap right now it's not financially viable to even try. There's enough extractable uranium dissolved in the world's oceans to power the world for millenia if we had to.
The Indian plan will work, it has no magic "And then a miracle occurs!" steps in the middle. It's just an alternative fuel cycle for HWBWRs and PWRs that everybody and their dog has been operating for over half a century. It's not a pure thorium-fuel cycle though. About 20% or so of the electricity generated in the third-stage reactors will be provided by the MEU (20% enriched, well on the way to bomb-grade) and the Pu in the fuel rods and of course the first two stages run completely without the involvement of thorium. Same for the molten-salt thorium reactor concept although it needs less Sparkly Stuff to kickstart it from cold. It still needs some regular cheap efficient uranium-fuelled reactors to be working somewhere to provide that Sparkly Stuff though, and in that case why bother with the thorium at all? It's not like uranium is in short supply or particularly expensive.
The planned Indian thorium PWRs have the same failure modes that TMI and the Fukushima reactors had, a loss of coolant resulting in a drastic overheat causing steam on the zirconium fuel rod jacketing to evolve hydrogen plus eventual meltdown of the fuel rods. The fission byproduct mix from the U-233 fuel bred from Th-232 won't be noticeably different from that resulting from U-235 and Pu-239/240, the M Curve with lots of Cs-134 and Cs-137, some I-131 etc. resulting in a great deal of decay heat, damage to fuel and the reactor vessel and possibly a containment breach if the loss of coolant is not dealt with promptly.
My nearest Apple store is over 50 miles away. That's a day out of my life to take it there and maybe another day to go collect it later. Then again I'm lucky that I have an Apple store (just the one though) in my native country.
The Samsung monitor I've got hooked up to this machine as a secondary display blew out on me a year or so back, but it was covered by a 3-year on-site swapout warranty at no extra cost. I had to wait a couple of days for the swap to take place but I didn't have to waste my time travelling hundreds of miles to get the damn thing replaced and I didn't need to post it anywhere either.
Most if not all decommissioning is paid for over the reactor's operating period. Some funds are not fully paid up yet as the reactors have only been operating for a decade or two or three. By the time they get shut down the funds will be paid up and a bit more probably.
Decommissioning an undamaged reactor isn't that expensive. It might take a few decades but nearly all of that will be waiting for some residual radioactivity to decay after the last load of spent fuel is removed. The rules about residual radioactivity are ridiculously tight in the US -- "scrap steel from gas plants may be recycled if it has less than 500,000 Bq/kg (0.5 MBq/kg) radioactivity (the exemption level). This level however is one thousand times higher than the clearance level for recycled material (both steel and concrete) from the nuclear industry, where anything above 500 Bq/kg may not be cleared from regulatory control for recycling." Weird isn't it? It's like folks are irrationally scared of nuclear power for some reason.
The operators pay for the waste storage and treatment too with another levy on the electricity generated. In the US that's about 0.1 cents US per kWh IIRC. The spent fuel, being nuclear material and therefore regarded as strategic is entrusted to the government to deal with. The total fund for dealing with the spent fuel is over 30 billion bucks and rising.
Finland's current fund for dealing with its spent fuel is well over a billion bucks, raised similarly by a levy on the generating companies. They're spending about 800 miliion bucks building an deep underground depository in granite that should handle a century's worth of spent fuel from their existing and planned reactors, with operating costs covered by the levy paid for by the electricity consumers.
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They did blow up two planet-sized Death Stars, killed millions maybe billions of people, contractors, construction workers, canteen staff, janitors etc. They gave medals to the grinning yahoos that did it.
Just sayin'
I live in the centre of a city with the best public bus service in the nation, operating at a profit with regular clean modern buses, express services to the airport, park-and-rides, good handicapped access, night bus services etc.
Despite this the big city centre employers like the financial services companies, healthcare, TV stations etc. all run their own shuttle bus operations as the public buses don't necessarily go from one office to another, although a few bus routes actually go into company campuses to pick up and drop off passengers at the office front door as well as passing through the business parks on the city outskirts.
Nobody's built a liquid salt thorium breeder (Th-232 -> U-233) reactor yet, and licencing the design in the West could take decades -- even conventional PWRs can take more than ten years from proposal to first concrete and they're proven designs, steam-boiler simple with no 700 deg C liquid fuel to cope with. Even according to the Powerpoint Rangers who are pushing LFTR as the Ultimate Fix For Everything Nuclear waste actinide destruction requires an enormous fast neutron flux only available by fissioning lots of U-235 and Pu-239 in the liquid salt stream and that will produce significant amounts of fission product waste, hopefully not as fast as it burns existing waste actinides if it is tweaked for that role -- the breeding process needs a lot of neutrons too and there may not be enough to go around to do both at the same time.
The liquid-salt thorium breeder system involves very high temperatures and radioisotope chemistry interacting with the piping over decades of use, not to mention the continuous reprocessing plant powered by handwavium which produces its own intensely radioactive waste stream. The track record of sodium-cooled plutonium breeders where the ceramic fuel doesn't move and the engineering and chemistry is better understood isn't too good -- lots of pipe cracks, coolant leaks, fires etc. over the years. LFTR makes a nice graduate student presentation at TED though, great slides with "and then a miracle occurs" in 8-point Comic Sans at the bottom.
The IFR and its cousins are less fanciful prospects, indeed Russia and China are actively (as in bending metal and pouring concrete) working on fast-spectrum reactors like the BN-800 and the proposed CDFR which will have the capability to burn actinides as part of their function but they too will produce lots of fresh fission products. The current fast-spectrum designs like the smaller BN-350 (operating in Russia since 1980) also generate electricity and breed plutonium from U-238 depending on their operational configuration.
Vitrification (what you Yanks call "glassification") is carried out to stabilise the waste from reprocessed fuel The US doesn't reprocess fuel on any sort of scale although it may process defence-related nuclear waste.
Typically a tonne of spent fuel will contain a couple of kilogrammes of actual waste fission products, the rest is nearly all uranium and a small amount of plutonium. Reprocessing and vitrification vastly reduces the physical volume of waste but it doesn't reduce the radioactivity emitted by it since uranium and plutonium are quite long-lived, it's the shorter-halflife waste isotopes that produce nearly all of the detectable radiation and residual heat in spent fuel.
The Izumo is a replacement for the existing smaller Japanese helicopter carriers and they plan to build a second one. Some defence-oriented website put up a scale comparison picture -- the Izumo is about the same size as the IJN fleet carriers like the Akagi that attacked Pearl Harbor in 1941. It's still significantly smaller than the USMC's Tarawa LHD carriers and the forthcoming America class replacements for the Tarawas are even bigger targets^W.
I can't actually think of a notable writer from Glasgow -- Alasdair Gray perhaps? Google Google wikiwiki yup, born in Riddrie and still lives in Glasgow. That's it. The Scottish Socialist Vanguard Science Fiction Writers Party is all on the east coast (Iain M. Banks (RIP), Ken McLeod, Charlie Stross, Hannu Rajaniemi etc.)
Capaldi's Glaswegian, not Boston Irish. Don't know why you went with an American dialect rather than something fae Glesca.
Rough translation into Barras Glaswegian -- "Haw, d'ye fuckin' ken who yer fuckin' dealin' way here? Well Ah'm th'fuckin' Doaktur ye bastardin' wee alien ba'heid, noo get fuckin' oota my fuckin' sight afore ah fuckin' stick th' fuckin' heid in ye!"
Ontario has brought some mothballed nuclear reactors back into service in order to shut down their existing coal-burning generating stations, with the last one due to close next year. There's a single gas-fired converted coal-plant and they're planning to develop a biomass fuel chain for one of the other plants. They do have a lot of hydro power though, typically about 6GW generating capacity at any given time. The nuclear fleet provides up to 6.6GW depending on the number of reactors running at any given time. Here's the real-time generating information for the assorted facilities Ontario Power run -- basically the nukes run flat out, the hydro generating sets throttle up and down and the thermal (mainly gas) power stations fill in the cracks.
The current designs of nuclear plants being built around the world have an initial design life of 60 years, not "a couple of decades". They may well go on operating for a century depending on maintenance, fuel costs etc.
The existing fleet of Gen II reactors built in the 70s and 80s are reaching the end of their initial licencing period of 40 years but after inspection and some upgrading here and there quite a few of them are getting a licence extension of ten years with the expectation that they could well get another 10-year operating extension on top of that.
I'd do a point-by-point refutation of your arguments but I can't be buggered. I'll just say if you think that piping a few hundred tonnes of incredibly hot and mind-bogglingly radioactive sludge through a moderating core and a continuous reprocessing plant for decades on end is not complex compared to a PWR where water is sprayed onto solid fuel rods in a pressure vessel then I don't know which planet you're living on.
If you can get past the PowerPoint Rangers and the graduate student "and then a miracle occurs!" presentations about MSRs and thorium breeders into the nitty-gritty of producing significant amounts of power from nuclear energy then the MSR concept falls down in a lot of aspects. It might be the greatest thing since sliced bread after a lot of expensive debugging but right now it's a solution (so to speak) in desperate search of a problem that doesn't really exist.
It's kind of difficult to think back that far but in the 70s space launches were complicated things, not run-of-the-mill operations like today. One of the constraints that resulted in the Shuttle design was the necessity to launch the crew and payload in one shot. The idea of launching two or three individual payloads and crew capsules within a few days of each other and have them make rendezvous in orbit was beyond the capability of anyone at the time. The Shuttle was basically a variant of the one-shot Apollo-Saturn stack for that reason.
When the Shuttle did fly it provided a shirt-sleeve environment for up to seven crew for up to 28 days (although they never flew that long), a large flexible payload bay and about 20 tonnes or so of lift capability, two-person spacewalk support with the ability to carry out multiple missions, quite a lot of delta-vee to move around or to change orbits, a toilet and a shower (sheer luxury for the spam-in-a-can capsule pilots of the previous generation and not something the SpaceX Dragon capsule or the Boeing offering is going to be fitted with) and it came back to land, not requiring an aircraft carrier group to go pick the crew up out of the Pacific 135 times.
If the Shuttle hadn't been as reusable as it was then I suspect the operating budget of whatever replaced it would have been trimmed back gradually and the end of US manned spaceflight in US-launched vehicles would have come a lot sooner and the ISS would never have been built, or at least not on the current scale.
I've been mulling over an idea about using spare lift capacity on launchers to implement this tank-farm idea, but not for hypergolic fuels as would be needed by landers, manned probes etc. Instead of carrying toy cubesats and such, if spare mass is available on a launcher use that capacity to loft standard-sized tanks of liquid argon or preferably xenon into LEO. This would be used as reaction mass in ion drive engines, already well-proven in various space applications.
After separating from the main launcher bus in LEO the liquid gas tank would be collected by a robot tug powered by ion drive and solar panels and taken to a tank farm in a higher orbit where atmospheric drag won't cause the tanks to re-enter. From there other ion drive-powered tugs fuelled by the liquid gas could take reaction mass up to GEO to top up some of the satellites there that are already using ion thrusters for stationkeeping. In addition any deep space probes that use ion engines can get fuelled up in orbit rather than having to carry their own reaction mass all the way up from the ground.
The tugs don't need to be very powerful, they're in no hurry as any vehicle they supply isn't going anywhere and can usually afford to wait for a few days or weeks to get fuelled up. It's not much use for manned flight and the like although it might help to power a pipeline for a manned Mars mission, helping to delivering robot supply vessels to Mars orbit in the same way Progress, ATV and the Dragon capsule supply materials to the ISS.
A surprisingly large amount of stuff sent into low earth orbit and even geosynchronous orbit consists of fuel and oxidiser. The Shuttle launched with over 14 tonnes of manoeuvering fuel and oxidiser on board for the OMS and RCS motors. That's 14 tonnes that couldn't be dedicated to payload, food, water etc. Similarly a geosynchrononous satellite weighing 6 tonnes will be carrying two or three tones of fuel and oxidiser so it can maneuver into its final orbit and allow it to maintain station for a decade or more. Some GEO birds have been decommissioned when they nearly ran out of fuel, not because they broke down or became obsolete.
Using a slingshot or other brute-force technique to put tanks of fuel and oxidiser into orbit cheaply could well be worthwhile; robot tugs could collect them into a tank farm of some kind in a higher orbit and then deliver fuel and oxidiser to various vehicles as needed rather than them having to lift their entire fuel and oxidiser loads along with delicate electronics, structural components for Mars landers, fleshy meatbags etc.
I think a long technical discussion of MSRs and thorium-breeders is outside the remit of the poo-flinging and "...xxx YOU!" jokes that normally goes on in typical Slashdot threads.
The base line is that any technology used to generate electricity has to work at a ticket price people are willing to pay with operating effects on the world they are willing to accept. Right now coal is king even though it kills thousands of miners each year extracting it, produces unconstrained toxic waste by the megatonne and is poisoning the atmosphere. The only upside is that coal is cheap and plentiful and there's lots more where it came from so it is used to generate over 40% of the world's electricity. Gas is less toxic but still loads the atmosphere with CO2, right now it's cheap if less plentiful than coal and doesn't kill lots of people extracting it. Conventional nuclear is about as cheap as coal per kWh of generation and doesn't emit CO2 but it has a number of perceived downsides most of which the nuclear industry will tell you have been fixed or can be fixed.
MSR technology is not going to solve that "perceived downsides" problem that the nuclear power industry labours under around the world -- it still involves fissioning uranium even if it's bred up from thorium, it still involves fission byproduct waste, it's still going to need large amounts of capital up-front to build commercial plants and cover all the regulatory costs of getting them built. MSR designs are not going to get a pass because it's much more complex than a steam-engine-simple PWR but THEORETICALLY safer. An MSR that produces commercial electricity at three or four times the cost per kWh of other baseload generators is not going to get funded in the first place, basically.
India is not a signatory to the Non-Proliferation Treaty (NPT), like North Korea, Pakistan and a few other countries who want to possess and develop nuclear weapons outside the treaty's limitations. As such other nuclear-capable nations are not permitted to supply it with nuclear materials and technology. This ban should include selling them uranium, fuel elements and other raw materials as well as engineering equipment, design expertise etc. In practice the US and some other countries skirt the treaty and help the Indians out as long as they promise not to divert the materials and equipment into their nuclear weapons development programmes.
The thorium-fuelled PWRs India is planning are clumsy affairs, effectively breeding and burning their fuel at the same time, producing less power per kiltonne of concrete and steel than a modern PWR. The fuel cycle is a lot more complex with inputs of medium-enriched uranium (probably from their military reactor fuelling programmes and weapons development) and scarcer plutonium, again derived from their military reactors. This is going to be significantly more expensive than conventional PWRs would be even if they bought in yellowcake and established their own fuel element manufacturing capability as other uranium-poor countries like China are doing.
Either they continue to keep the IAEA inspectors out of their military nuclear facilities by remaining outside the NPT umbrella or they pay for it by spending more to keep this jackleg fuel cycle running due to an inability to buy uranium on the open market at firesale prices. It's their choice.
I have a car but I live in a city centre, it takes me at least half an hour to get to the outskirts through a maze of twisty little roads. After that it's about 40 minutes by motorway then another half-hour to get to the city-centre store where there's no local parking as it's in a pedestrian shopping street so I would have to park some distance away and walk. Time at the store, wait wait wait, then reverse the process. Four or five hours at least and it has to be done during the store's opening hours so I can't do this in the evening after work. That's a day taken up pretty much.
It's actually easier and cheaper for me to take the train if I need to go there, assuming I'm OK carrying whatever it is needs fixing - a 30" Thunderbolt display is not a small bundle to tuck under one arm.
The utilities are required by US law to hand over control of spent fuel to the government and pay for its disposal. They've done that, the government generally hasn't taken it away as they said they would and the only major attempt to build a spent fuel depository at Yucca Mountain turned into a congressional pork project and then was cancelled after about $9 billion was spent building it.
Uranium is cheap because there's a lot of it about. The warheads-into-fuel projects currently operating only provide a few tonnes of fuel per year for the world market -- the entire world's stockpile of nukes amounting to about 25,000 warheads in the late 1960s contained maybe 200 tonnes of highly-enriched uranium and Pu-239 in total and a single 1GW PWR will burn a couple of tonnes of U-235 or Pu-239 each year. I did a rough calculation once and figured the entire American stockpile of nuclear weapons could provide the nation's electricity demands for about two weeks, no more.
The insurance thing is a lie. The utilities are required to carry large amounts of liability insurance, up to about $10 billion or so under the Price-Anderson Act. After that the government is the insurer of last resort in the same way they're spending fifty billion dollars to rebuild in New York and Jersey after Hurricane Sandy hit, overwhelming the flood and disaster insurance market there. Ditto for Katrina and New Orleans etc. The second-worst nuclear power accident in US history at TMI never required asking the US government for funds despite the operators spending tens of millions dealing with lawsuits. The cleanup operation is only costing a few hundred million bucks total. Before you ask the worst accident was the SL-1 reactor incident in the 1960s as there were three fatalities unlike TMI where there were no casualties at all.
As for thorium, again I have to explain that Th-232 is not a nuclear fuel. It can be bred into U-233 by exposing it to a neutron flux, most easily by putting it into moderated proximity to real nuclear fuel like U-235 and Pu-239/240 at which point via spontaneous and induced fission the U-233 produced will release energy with all the benefits and downsides of its kissing cousin isotope U-235. Th-232 by itself just sits there.
The liquid-fluorine thorium reactor so beloved of the Powerpoint Rangers is a BREEDER reactor, not something they ever emphasise in their TED Talks because breeders have a bad rep in the nuclear world, expensive and uneconomic hangar queens even when they've not broken down or leaked their coolant/moderator over the floor and/or caught fire. Given that MSR designs are even more complicated than "conventional" breeders I'm not surprised they don't emphasise the B-word.
You want nasty? Imagine going deep underground and digging coal out of wet gassy seams, transporting it hundreds of miles and burning it in power stations and dumping the fossil carbon into the atmosphere as CO2. Well, actually humanity does that today -- 7.6 billion tonnes of coal or thereabouts were produced and burnt in 2011 alone to generate less than 40% of the world's electricity demand.
In comparison the world's fleet of about 400 power reactors, generating about 20% of the electricity used in the world consume less than 50,000 tonnes of uranium a year. The extra cost of processing and enriching the fuel is a pittance given the high energy density per gram of fuel -- the biggest costs for nuclear power stations are the operations (salaries, inspections, maintenance, landscaping etc.) and paying the loans that built the plant in the first place. Fuel costs even after enrichment etc. is about 0.7 cents/kWh.
The "seed" for thorium reactors is actually U-235 and Pu-239/240, U-233 is what thorium (Th-232) has to be "bred" into by absorbing a neutron before it can create recoverable energy by fissioning from a neutron impact. After that it's just like a regular reactor, fission products, decay heat, and all.
There is no engineering knowledge about how steel alloys cope with direct contact of highly radioactive molten salts at 700 deg C for decades on end. It could be very expensive to find out the hard way if the alloys chosen don't stand up very well to the conditions. We know a lot about how reactor vessels, pumps and piping exposed to high-pressure steam at 300 deg C and limited neutron bombardment for decades on end perform because there are hundreds of reactors out there as operating testbeds, and the knowledge base says they do pretty well at it.
Neutron embrittlement does happen, as does some activation by fission or more commonly neutron capture but the major structure in a PWR, the reactor vessel itself is massively overengineered for decades of expected troublefree operation. It's a giant pressure-cooker with no moving parts, all it has to to is endure the heat and pressure and it never comes in contact with hot fuel, only water and steam. It certainly receives a lot of neutron flux but the walls of the vessel are some distance from the core and the internal structures which carry the fuel rods, the water injectors, control rods etc. Compare that to the amount of neutron flux the piping, heat exchangers etc. in a LFTR will be exposed to as they are in direct contact with the highly radioactive fuel and decay products for decades on end and at high temperatures. Decommissioning that piping at end-of-life will be a radiological nightmare.
As for byproducts I hope you realise that the heat energy from thorium fuel in LFTRs and even the Indian MOX PWRs actually comes from fissioning U-233 and that fission process results in the same isotopes that are produced in a regular U-235-fuelled PWR, if in slightly different percentages. The awkward medium-life products still have to be dealt with like Cs-137 (half-life of 30 years) and its close friends.
Power reactors didn't produce weapons-grade plutonium anyway. PWRs and such salt the Pu-239 they breed from U-238 with Pu-240 when it captures another neutron and that screws up implosion weapon designs to the point where they don't work right if at all. There were some dual-use reactor designs like the British Magnox and the Russian RMBK-4 that could be operated to breed purer forms of Pu-239 but by the time they came on-line in the 60s the major Powers had made all the Pu-239 (a few hundred tonnes in total) they'd ever need from dedicated short-cycle breeder reactors in places like Hanford and Windscale. You don't need reactors at all to build U-235 weapons of course, just enrichment facilities.
The good news is that molten-salt thorium reactors work by breeding Th-232 into U-233 and that can be easily extracted and turned into quite usable nuclear weapons (the US fired off a couple of test U-233 shots in the 50s, I don't know if the Soviets ever did). Given that a molten-salt thorium reactor positively requires a reprocessing plant which can extract the U-233 to keep it running is just another bonus for any wannabe new entrants to the nuclear weapons club assuming molten-salt thorium ever gets productionised.
Molten-salt thorium reactors are currently in the Powerpoint stage of development with a lot of handwaving over parts of the design involving really problematic engineering and logistical hiccups. For example the highly radioactive molten-salt fuel has to circulate at about 700 deg C though piping, pumps and heat exchangers -- most steel alloys lose half their strength at those sorts of temperatures and if a joint goes bad then you can expect a disaster in the containment or worse still in the steam generating plant. See the various metallic sodium leaks the breeder builders have suffered over the years for a worked example. The fuel stream has to be continually reprocessed to remove fission products that would poison the reaction by absorbing neutrons, not something the 1960s experimental molten-salt test reactor ever attempted to do. These reprocessing stacks will be highly radioactive for centuries or even millenia, assuming they last long enough for the reactor to run for more than a couple of years before breaking down and they will be horrendously expensive to decommission. Etc. Etc.
In comparison the fuel in a PWR or other power reactor is a solid ceramic pellet (melting point about 2200 deg C) that sits in a zirconium fuel rod jacket and doesn't go anywhere unless a disaster happens. When the refuelling operation happens the spent fuel rod assemblies are taken away and stored in a pool for a few years to cool down and let the decay heat from the fission products fall to a level where storage in air will suffice without the rods overheating. After that they can be buried or, depending on circumstances, reprocessed to reduce the volume of real waste to a few percent of the original fuel pellets and the unspent fuel recycled. And that's it, no Powerpoint Rangers, just 60 years and more of actual real-world reactor operations experience.
Some of the richest uranium deposits known are in northern Canada, in locations so remote they'd have to fly the yellowcake (uranium oxide in the form of U3O8) out in cargo planes. Today the spot price (25th July 2013) for yellowcake is $40 per lb. which makes it uneconomic to work that ore body given the logistics costs involved. If the price of yellowcake tripled then maybe it would start to be worthwhile opening up those orebodies. That tripling of the raw material price would only increase the price of nuclear-generated electricity by about 1.5 cents per kWh though because the fuel is still ridiculously cheap and a minor part of the total cost of nuclear electricity.
Long time back before WWII, nobody was really interested in uranium, it had little or no industrial uses. After WWII everybody started looking for it but it was thought at that time it was rare hence the early interest in thorium, breeder reactors etc. It turned out that it was actually quite a common substance with lots of easy-to-mine ore bodies in places all over the world. We're still working on the easiest to extract sources of uranium because they're cheap. As they run out we'll dig up more expensive ores, lesser grades requiring more digging and processing and the price will rise.
The wonderful thing is that uranium is so compact a source of energy that we don't need to dig up a lot of ore to keep the lights on, not compared to coal or oil or gas. The US' entire electricity demand could be met by a couple of million tonnes of uranium ore each year, without reprocessing spent fuel -- if that was done (at a price) a few hundred thousand tonnes of ore would suffice. In comparison it would take about 4 billion tonnes of coal each year to do the same job.
The bottom line price for uranium is extraction from seawater -- Japanese experiments suggest that would cost about $300 per kilo of uranium metal although nobody's bothered to build a pilot extraction plant because, guess what, uranium is so cheap right now it's not financially viable to even try. There's enough extractable uranium dissolved in the world's oceans to power the world for millenia if we had to.
The Indian plan will work, it has no magic "And then a miracle occurs!" steps in the middle. It's just an alternative fuel cycle for HWBWRs and PWRs that everybody and their dog has been operating for over half a century. It's not a pure thorium-fuel cycle though. About 20% or so of the electricity generated in the third-stage reactors will be provided by the MEU (20% enriched, well on the way to bomb-grade) and the Pu in the fuel rods and of course the first two stages run completely without the involvement of thorium. Same for the molten-salt thorium reactor concept although it needs less Sparkly Stuff to kickstart it from cold. It still needs some regular cheap efficient uranium-fuelled reactors to be working somewhere to provide that Sparkly Stuff though, and in that case why bother with the thorium at all? It's not like uranium is in short supply or particularly expensive.
The planned Indian thorium PWRs have the same failure modes that TMI and the Fukushima reactors had, a loss of coolant resulting in a drastic overheat causing steam on the zirconium fuel rod jacketing to evolve hydrogen plus eventual meltdown of the fuel rods. The fission byproduct mix from the U-233 fuel bred from Th-232 won't be noticeably different from that resulting from U-235 and Pu-239/240, the M Curve with lots of Cs-134 and Cs-137, some I-131 etc. resulting in a great deal of decay heat, damage to fuel and the reactor vessel and possibly a containment breach if the loss of coolant is not dealt with promptly.
My nearest Apple store is over 50 miles away. That's a day out of my life to take it there and maybe another day to go collect it later. Then again I'm lucky that I have an Apple store (just the one though) in my native country.
The Samsung monitor I've got hooked up to this machine as a secondary display blew out on me a year or so back, but it was covered by a 3-year on-site swapout warranty at no extra cost. I had to wait a couple of days for the swap to take place but I didn't have to waste my time travelling hundreds of miles to get the damn thing replaced and I didn't need to post it anywhere either.
Most if not all decommissioning is paid for over the reactor's operating period. Some funds are not fully paid up yet as the reactors have only been operating for a decade or two or three. By the time they get shut down the funds will be paid up and a bit more probably.
Decommissioning an undamaged reactor isn't that expensive. It might take a few decades but nearly all of that will be waiting for some residual radioactivity to decay after the last load of spent fuel is removed. The rules about residual radioactivity are ridiculously tight in the US -- "scrap steel from gas plants may be recycled if it has less than 500,000 Bq/kg (0.5 MBq/kg) radioactivity (the exemption level). This level however is one thousand times higher than the clearance level for recycled material (both steel and concrete) from the nuclear industry, where anything above 500 Bq/kg may not be cleared from regulatory control for recycling." Weird isn't it? It's like folks are irrationally scared of nuclear power for some reason.
The operators pay for the waste storage and treatment too with another levy on the electricity generated. In the US that's about 0.1 cents US per kWh IIRC. The spent fuel, being nuclear material and therefore regarded as strategic is entrusted to the government to deal with. The total fund for dealing with the spent fuel is over 30 billion bucks and rising.
Finland's current fund for dealing with its spent fuel is well over a billion bucks, raised similarly by a levy on the generating companies. They're spending about 800 miliion bucks building an deep underground depository in granite that should handle a century's worth of spent fuel from their existing and planned reactors, with operating costs covered by the levy paid for by the electricity consumers.