Re: Several votes for Thorium
Thorium is considered the nuclear fuel of the future (and has been for about 40 years now) for a number of reasons.
Thorium ore is easy to extract and the most common form - monazite - is found as a heavy sand in and around rivers and beaches. It can literally be scooped up. There are several times as much thorium in the crust as uranium. It's also widely distributed so it doesn't have any economic bottlenecks (unlike the rare earths or lithium). There are enough known thorium reserves to last about 1000 years, without any new discoveries. In the US thorium is getting a real boost because America has by far the largest known reserves of the metal (followed by India - a fellow thorium booster).
It's pretty much pure Th-232 which when exposed to neutrons produces fissile U-233 without any of the unwanted isotopes of uranium (such as U-238 which is converted into plutonium in the reactor).
Because you can separate Th-232 from U-233 with relatively simple chemistry, the fuel cycle is simplified and there is much less actinide waste.
Thorium-breeder reactors will be simpler and cheaper to build than uranium-breeder reactors which use liquid metal cooling and have always been prone to leaks.
The downsides of thorium are that despite a lot of research, especially in India, no thorium reactor has yet been approved for mass production by regulators. The Indians have a 300MWe plant under construction which, *if* successful, will form the prototype for a fleet of power reactors.
The second issue with thorium power, which could kill it stone dead, is that U-233 is fast fissile and can be used in nuclear weapons. If thorium were to become a major energy source it does raise the proliferation risk - somehting that should be addressed now, rather than later.