I can not figure out why more effort is not put into thorium nuclear technology research. The only reason I have heard why thorium is not being considered is because it is not weaponizable. Are there any other reasons why thorium based nuclear fission is not being pursued as an energy source?
From what I've heard, it's because we've now got decades of experience engineering uranium fission reactors, during which we've learned tons about the practical engineering challenges involved. While thorium looks great on paper, engineers expect we'll need decades of working with it before a similar body of expertise is available, during which accidents may occur that we know how to avoid with uranium, etc.
In other words, without uranium being scarce and expensive, and with thorium being lumped in the same "nuclear" bucket (with all the political hurdles that implies), it doesn't make much economic sense to start over with thorium.
I was just about to ask the same question. I hadn't heard of Thorium-based nuclear power until now, so I just read a summary of it on Wikipedia [1]. It seems like a promising technology for further research, so I'm wondering what the source is for the "Thorium? Not again" reactions.
The technology has not been fully developed, there only have been research reactors. Developing reactors for it would require significant investments and apparently no government is willing to invest in it.
That was a solid-fuel reactor. The one people are excited about these days is liquid-fueled. Oak Ridge built a couple small reactors in the 50's and 60's.
Liquid fuel brings several advantages, like being able to extract fission products that poison the reaction, giving you very high fuel efficiency. And if it overheats, a frozen plug melts and drains all the fuel into a tank designed to passively cool it.
It can't melt down, it has relatively save spent fuel, its plentiful, reactors can be turned on and off with a switch, a Thorium reactor can be constructed at any size efficiently. Seems like a lot of advantages.
I agree - it probably would be significantly cheaper and safer.
But it will also cost a lot of money to develop, and even though it's safer, it's still nuclear, i.e. opposition to it will be unchanged. The worst is some people are demanding that they be installed with full containment domes, which wipes out any cost savings.
Anyone who wants to actually install one will probably be stymied, so no one wants to spend the money to develop something they can't use. And especially not if it costs the same as a regular reactor.
Instead people just stick with the tried and true since it minimizes risk of failure.
The weaponizable argument was why research was shut down in the first place (also, pressurized water reactors were more useful for the US's naval fleet).
Uranium is cheap in most places, and we're already set up to use it. In order for thorium to be compelling, you need to either have problems with your uranium supply, or reactors that take advantage of its properties to be better in other ways.
That's why thorium is not a bigger priority. There is some R&D on it; for example, the Chinese pebble bed reactor program is working on using thorium.
I guess this is the natural outcome, when we expect the government to be the driver of scientific research. When the ones controlling the purse are also the ones we hold responsible for defense, then defense is bound to be a core focus of what gets researched.
