Why Thorium? 8. Radioactive waste from a Liquid Fluoride Thorium Reactor decays down to background radiation in 300 years compared to a million years for U-235 based reactors. A Limerick.

The nuclear waste meant for Yucca

would destine Nevada the sucka

But with Thorium we rid

us of waste that is hid

No need for that waste to be trucka!

Radioactive waste from an LFTR (Liquid Fluoride Thorium Reactor)  decays down to background radiation in 300 years instead of a million years for U-235 based reactors. Initially LFTRs produce as much radioactivity as an U-235 based nuclear reactor, since fission converts mass to heat, but the decay products have a much shorter half-life. See the figure below.

Where is the storage for spent nuclear fuel and other nuclear waste now? Look at the map, it is scary.

And these are just the U.S. installations!

Many years ago I studied Engineering at Chalmers’ University in Sweden and I thought I would become a nuclear engineer. Sweden had at that time a peaceful heavy water based nuclear power program together with Canada and India. The advantage with heavy water as moderator is that it can use natural, un-enriched Uranium. One of the end products is of course Plutonium 239, the preferred material to make nuclear bombs, but it could also use Thorium, and the end product is then mostly Plutonium 238, used in space exploration, and we were dreaming big. One of the advantages of Thorium as fuel is that it produces about 0,01%  of trans-Uranium waste compared to Uranium as fuel. About that time the U.S. proposed we should abandon the heavy water program and switch to light water enriched Uranium based nuclear power. They would sell the enriched Uranium, and reprocess the spent fuel at cost. They also had the ideal final resting place for the radioactive waste products in Nevada. This was an offer the Swedish government could not refuse, at the height of the cold war. This was  in the 1960’s! India on the other hand did refuse, and they eventually got the nuclear bomb. Since that meant Sweden was never going to use Thorium as nuclear fuel, and I could not figure out how to get rid of all the radioactive waste products, I switched my attention back to control engineering.

.What did President Trump mean with innovative approaches?

Is this where Thorium comes in!? Thorium solves many problems with nuclear energy. Meanwhile the Biden administration and Congress keep hoarding nuclear waste in local storages.