How About a Megatons To Megawatts Program For US Nuclear Weapons? 146
Lasrick writes "Dawn Stover looks at the incredibly successful Megatons to Megawatts program, which turned dismantled Russian nuclear warheads into lower-grade uranium fuel that can be used to produce electricity. The 1993 agreement between the U.S. and Russia not only eliminated 500 tons of weapons-grade uranium, but generated nearly 10% of U.S. electricity consumption. The Megatons to Megawatts program ended in December, but Stover points out that the U.S. has plenty of surplus nuclear weapons that could keep the program going, without the added risk of shipping it over such huge distances. A domestic Megatons to Megawatts, if you will. This would be very cost effective and have the added benefit of keeping USEC, the only American company in the uranium enrichment field, in business."
Re:No we should not (Score:5, Informative)
No. We should maintain our advantage over other nations. Especially China. After all China is probably building up a giant stockpile of nukes right now as we speak!!.
I realize this is /., so to rtfa is just crazy talk. But I did skim through it. We currently have 3000 retired warheads that are simply sitting in storage decaying. These aren't sitting on top of missiles. Or even being maintained. They are costing taxpayers who knows how much money to sit in a building somewhere. Since the cost of enriching this stuff beyond what is needed to generate power has alread done. This seems like an even bigger waste to me. As they would probably have to reprocess it to use in a weapon again anyhow.
Re:Burn the Uranium in safe Thorium reactors... (Score:5, Informative)
Not true. Thorium reactors could run exclusively on U-235 long term. It would be stupid to run them long term on U-235, but possible. But for startup, that's just what is planned to do. Thorium reactors could be started with a mix of U-235, Pu-239, Pu-240 and U-233.
Th-232 is a fertile material, U-233 is made from Th-232 after the reactor is running.
Once the reactor is in full operation, it makes more U-233 than it consumes, hence a breeder. Not all reactors that run Thorium are breeders (make more U-233 from Thorium than it consumes U-233).
Little U-233 is available worldwide, USA stockpiles are less than enough to start 10 Thorium reactors (even the designs that need the least fissile material in operation). Thorium reactor designs that need a larger fissile inventory might consume that U-233 just to startup two reactors.
The real problem with thermal reactors is U-238 making Pu-239, and Pu-239 only fissioning 2/3 of the time with thermal spectrum neutrons. When Pu-239 don't fission it makes Pu-240 leading to Americium and Curium production, leading to eating away extra neutrons.
The problem is that U-238 -> Pu-239 -> Fission or Pu-240 cycle in the thermal spectrum makes only 1.9 neutrons for each 2 consumed.
But if you have a stockpile of Pu-239, it only takes one neutron to make 1.9 neutrons on average, so it could startup a Thorium LFTR, producing U-233 from Th-232, and whatever Pu-240, Am-241 and Curium is made is kept in the reactor until it fissions.
Perhaps you mean for a Thorium breeder reactor (that makes as much U-233 as it consumes, or a little more), shouldn't be fueled with U-235, since it's a rare isotope (hundreds of times more rare on earth than Th-232), so it's not a good idea to run a Thorium reactor with U-235 on purpose.
Re:They already were, as part of the first program (Score:4, Informative)
Ummm, no. The economic factor for Super-Phenix shutting down was that it was an engineering prototype that pushed the envelope a bit too far in various directions. It broke in interesting ways, some due to the liquid sodium coolant, some because of the very intense neutron flux in a very small volume. The fact that the Greens fired a few RPG-7s at it in its early days had little to do with its eventual shutdown. This is La Belle France, remember -- see what they did to the Rainbow Warrior for what they think of Greenpeace.
The folks pushing next-generation breeders such as the assorted LFTRs, travelling-wave and other IFRs and the like have learned from the failures of the early breeder designs but it's likely they will run into other whoopsies themselves as they try to run productively for decades on end at 5 cents/kWh.
Re:Burn the Uranium in safe Thorium reactors... (Score:5, Informative)
No, proposed thorium breeder reactors like the LFTR breed Th-232 up into fissile U-233 and then fission that to produce energy and enough neutrons to continue the breeding cycle. The kickstarter fuel load with U-235 and Pu-239 initiates the breeding operation (hopefully, it's never been tested for real).
Breeding thorium has been done on a small scale in pebble-bed reactors using a small amount of thorium in the pebbles but relying on most of the fissiel fuel being U-235 to provide sufficient neutron flux to do the breeding which was not sustainable otherwise.
A worry with most of the LFTR designs is that commercial companies will have access to bomb-grade Pu-239 which can be chemically extracted from the kickstarter fuel load. MOX fuel for conventional PWRs has too much Pu-240 in the mix to build functional weapons from.
Re:They already were, as part of the first program (Score:4, Informative)
Personally, I would prefer that Plutonium be reserved for RTGs for space power. Outside of the inner solar system, solar-powered probes just don't cut it.
Re:We need the fuel! Other factors at play (Score:2, Informative)
Easily dis proven:
"Uranium mining in the United States produced 4.8 million pounds of uranium concentrate in 2013, the largest amount since 1997"
http://en.wikipedia.org/wiki/Uranium_mining_in_the_United_States
With mines in 21 states, it is hard to imagine the scenario that you state