The interesting thing in that 'Fuel cycle' passage is it keeps saying how it won't produce weapons metal, but then it keeps also noting the weapons metal can be extracted at various steps. That's a bit disingenuous, since extracting it is what makes it available in concentrated form for further concentration into weapons-grade material.
True, however the point that is downplayed in all the hype is that Thorium itself will not sustain a chain reaction......meaning that in order for a reactor to function, there must be a steady supply of emissions from either U-235 or Plutonium, at very close to weapons-grade enrichment levels to sustain the reaction. Granted, it's used only as an "initiator", and not consumed in the fuel cycle......however, it's still there. I can't see an advantage from the waste handling/disposal perspective either.
From strictly an engineering point of view, the only advantage to Thorium reactors is that the fuel requires little, if any enrichment.
Close to weapons-grade fissile material will always be present in a reactor, regardless of fuel, the only difference is the quantity and ease of access. The hype also claims that since the Thorium reaction is not self-sustaining, that many of the present reactor safety systems, and emergency cooling systems will not be needed.......I suspect that is a good part of Sparky's problem with them, along with the liquid salt/heavy water design. The Russians used a liquid Sodium reactor design (similar to this) on many of their nuke boats which, from a safety perspective were rightfully dubbed "widowmakers".........
Thorium-LSHW, and conventional liquid Sodium cooled reactors can be built
very small (in cubic feet of reactor per KW of output), however the coolant is highly reactive.......a tiny leak in an enclosed environment can be critical (further, refueling and cooling system maintenance is a nightmare). Current light water designs, with all of their foibles and backup requirements are (at least in practice) much safer in the long run (at least to those required to operate and maintain them).
A Note on Nuclear Power Plants, Waste, and Terrorism:
A great deal of the paranoia surrounding nuclear power, its waste products, and terrorism, is engendered by the possibility of someone making one of two types of devices. First, a "dirty bomb" which is a conventional explosion designed to dispurse radioactive material over a wide area (these ARE NOT nuclear explosions). In the event such an event were planned, it is far more likely that medical radiological material would be used for a couple of reasons: First, it's much more widely available, and second, subject to far less security.......the average large urban hospital oncology unit would have enough isotopic material for such purposes.
The second.....an actual nuclear weapon, is far more complex. Such a device would require between 2.5 and 10.5 kg of weapons-grade material, and the know-how to put it together successfully. Making a "gun-type" weapon is fairly straightforward, but vastly inefficient, prone to "fizzle" (and nearly impossible to radiologically conceal). A "lens-type" device is far more powerful, and several orders of magnitude more complex to build. It is significantly more likely that any group bent on such an event would procure a weapon from someones existing arsenal than attempt to construct it themselves.
Neither scenario places nuclear power plants very high on the list of resources.
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