3 ms·

Also, nearly identically, in uranium-based molten salt reactors. The safety and sustainability that enticed e.g. Andrew Yang to like thorium are actually comin

Also, nearly identically, in uranium-based molten salt reactors. The safety and sustainability that enticed e.g. Andrew Yang to like thorium are actually coming from low-pressure coolant and the concept of breeding, both of which are possible with thorium or uranium fuel cycles. The thorium itself has nearly nothing to do with either benefit. It's basically a rebranding of non-light water reactor nuclear. Thorium has one major primary physical differentiator, which is that it alone allows breeding with slow neutrons. Uranium needs fast neutrons to breed. Both options have pros and cons that basically wash out.

PaulHoule 6y ago
Th and U are soluble in F salts, but Pu isn't. A molten salt reactor that breeds U238 would have to be based on a Cl chemistry which is not so developed. Otherwise you'd get Pu plating out on your heat exchangers, clogging pipes, etc. What makes the LWR non-viable since 1980 or so is not the uranium or even the LWR, but the steam turbine it is attached to. The power density of a steam turbine is at least an order magnitude less than that of the gas turbines that are used to generate electricity today. To a first approximation, the cost of something is proportional to it's volume or mass. As it turns out, even if the heat was free the steam turbine alone attached to an LWR would make the cost of electricity uncompetitive. In fact, this is what mostly killed coal. If nuclear power is going to have any economic impact we have to ditch the steam turbine for a closed-cycle gas turbine and ditch the LWR for something that operates at higher temperature. Unfortunately the last time people were writing about the topic seriously (1970s) people thought the motivation to go to another reactor type was that we'd run out of U235, not that gas turbine generators would come online and wreck steam turbine economics.

PaulHoule 6y ago

Th and U are soluble in F salts, but Pu isn't. A molten salt reactor that breeds U238 would have to be based on a Cl chemistry which is not so developed. Otherwise you'd get Pu plating out on your heat exchangers, clogging pipes, etc. What makes the LWR non-viable since 1980 or so is not the uranium or even the LWR, but the steam turbine it is attached to. The power density of a steam turbine is at least an order magnitude less than that of the gas turbines that are used to generate electricity today. To a first approximation, the cost of something is proportional to it's volume or mass. As it turns out, even if the heat was free the steam turbine alone attached to an LWR would make the cost of electricity uncompetitive. In fact, this is what mostly killed coal. If nuclear power is going to have any economic impact we have to ditch the steam turbine for a closed-cycle gas turbine and ditch the LWR for something that operates at higher temperature. Unfortunately the last time people were writing about the topic seriously (1970s) people thought the motivation to go to another reactor type was that we'd run out of U235, not that gas turbine generators would come online and wreck steam turbine economics.