The case for Thorium. 7. Thorium based nuclear power is not suited for making nuclear bombs.

 Thorium based Nuclear Power does not produce much Plutonium-239, which is the preferred material used in nuclear bombs. The higher Plutonium isotopes and other TRansUraniums are about as nasty as they get, need expensive protection against terror attacks, and need to be stored for a very long time.

One anecdote from my youth. The time had come to apply to University, and to my delight I was accepted to Chalmers’ University in Sweden as a Technical Physics major. I felt, maybe I can do my part by becoming a Nuclear Engineer and help solve the energy needs of the future. The Swedes at that time championed the heavy water – natural Uranium program together with the Canadians. Sweden is a non-aligned country, so it was not privy to any atomic secrets, it had to go it alone. They settled on the heavy water moderated natural Uranium process because Sweden had an ambition to produce its own nuclear bomb. Officially this was never talked about, and I was not aware of it at that time. They could have gone with Thorium instead, but a Thorium based nuclear reactor  produces very little Plutonium, and what it produces is nearly all Pplutonium-238, not fissile and as such not suitable for bomb making.

I was excited to learn about all the possibilities and signed up for a couple of nuclear classes. One lab was to design a safety circuit, then run the heavy water research reactor critical and hopefully watch the reactor shut down from the safety circuit before the system safety circuit shutdown. About that time the word came that U.S. will sell partially enriched uranium at bargain basement prices if Sweden agreed to abandon the heavy water project and sign the nuclear non-proliferation treaty, a treaty being formulated by U.N.

Sweden was in awe about U.N, all the problems of the world were to be solved through it, and it had such a capable General Secretary in Dag Hammarskjöld, a Swede. I looked at the light water, partially enriched Uranium nuclear power plants being developed and decided to have no part with it, not due to safety concerns but it was the design that produced the most nuclear waste of any of the available designs. At that time there was still optimism that fusion would be ready by about the year 2010 or so. The cost of maintaining spent fuel in perpetuity was never considered, so light water reactors became the low cost solution.

India on the other hand refused to join the nuclear non-proliferation treaty, kept their heavy water program going and had by 1974 produced enough plutonium for one nuclear bomb, which they promptly detonated. They still use heavy water moderated reactors, but since India is low on Uranium but rich in Thorium they have now converted one heavy water reactor to Thorium with a Plutonium glow plug. It went on-line in 2011.

They are also developing molten salt Thorium reactors, but full production is still a few years off.

There we have it. We could have gone with Thorium from the beginning, but the cold war was on, and the civilian peaceful use of nuclear energy was still all paid for by nuclear weapons research and development. Once all the bombs we could ever wish for were developed the greatest asset of nuclear power became its greatest liability.

The case for Thorium. 4. Thorium based nuclear power will produce Plutonium-238, needed for space exploration.

A Thorium based nuclear power generator produces Pu-238 as one of the final TRansUranium products, which is in short supply and much in demand for space exploration nuclear power.

NASA relies on pu-238 to power long-lasting spacecraft batteries that transform heat into electricity. With foreign and domestic supplies dwindling, NASA officials are worried the shortage will prevent the agency from sending spacecraft to the outer planets and other destinations where sunlight is scarce. Thorium reactors produce PU-238 as a “free” byproduct.  In 2009 Congress denied a request to produce more Pu-238 by traditional means, instead relying on Russia to sell us the plutonium. (Remember the Russian reset?) Russia made their last delivery in 2010. PU-238 production has since been restarted by converting Ne-237 to Pu-238 at a cost of over 8 million dollars per kilogram. The Ceres-Dawn spacecraft used over 22 Kg of Pu-238 as electricity generator.

To get the best efficiency of generating Pu-238 out of a molten salt Liquid Fluoride Thorium Reactor, the excess U-233 and TRansUranium products have to be extracted continuously while the reactor is running, and this technology is not yet implemented, but is necessary to implement before we can also have Thorium power on the moon, and Thorium Power is the only viable solution if we are ever going to have a moon colony, so we should get to it.

The need to develop Thorium based Nuclear Energy as the major electric energy supply. 4. Thorium based nuclear power produces Pu-238, needed for space exploration.

A Thorium based nuclear power generator produces Pu-238 as one of the final TRansUranium products, which is in short supply and much in demand for space exploration nuclear power.

NASA relies on pu-238 to power long-lasting spacecraft batteries that transform heat into electricity. With foreign and domestic supplies dwindling, NASA officials are worried the shortage will prevent the agency from sending spacecraft to the outer planets and other destinations where sunlight is scarce. Thorium reactors produce PU-238 as a “free” byproduct.  In 2009 Congress denied a request to produce more Pu-238 by traditional means, instead relying on Russia to sell us the plutonium. (Remember the Russian reset?) Russia made their last delivery in 2010. PU-238 production has since been restarted by converting Ne-237 to Pu-238 at a cost of 8 million dollars per kilogram. The Ceres-Dawn spacecraft used over 22 Kg of Pu-238 as electricity generator.