Bill Nye once on gender probability, A Limerick.

What makes you a girl or a boy?

As Chromosomes unfurl with joy

its XX or XY

only 2, and that’s why

it’s woman or man, let’s enjoy.

Or, as the French say: Vive la différence! But then again, the French have a fully gendered language. Everything has a gender, male or female, nothing transgender.

We have come a long way. Bill Nye, the “Science Guy” in 2017 showed a skit on Netflix that cannot be reposted here, it is so gross, essentially claiming that anything goes sexually, and anything is “morally” equivalent. (By objecting to it, I guess it makes me a homophobic, transphobic, xenophobic, omniphobic hater.) Or, maybe I am like the Bill Nye of the 1990’s, here using a girl to explain probability.

From this we learn that the Bible is right:

Genesis 1:27, KJV  So God created man in his own image, in the image of God created he him; male and female created he them.

This is not hate, it is God-given biological truth.

The need to develop Thorium based Nuclear Energy as the major electric energy supply. 13. Thorium Nuclear Power generators  scale  beautifully from small portable generators to full size power plants.

Thorium Nuclear Power generators  scale  beautifully from small portable generators to full size power plants. One of the first applications was as an airborne nuclear reactor.

Granted this was not a Thorium breeder reactor, but it proves nuclear reactors can be made lightweight. Thorium reactors can be made even lighter as long as they are not of the breeder type.

The need to develop Thorium based Nuclear Energy as the major electric energy supply. 12. Virtually no spent fuel problem, very little on site storage or transport.

 Virtually no spent fuel problem, very little on site storage or transport. I am following the events at Fukushima Nuclear Power plants with great interest. How ironic that the greatest risk is with the spent fuel, not with the inability to shut down the working units. The spent fuel issue is the real Achilles’ heel of the Nuclear Power Industry. Molten Salt Thorium nuclear power works differently from  conventional Uranium as  the fissile fuel gets generated in the breeding process itself and nearly all fuel gets consumed as it is generated. When the process shuts down, that is it. Only the radioactivity that is en route so to say will have to be accounted for, not everything generated thus far in the process. The difference is about one to ten thousand in the size of the problem. It is high time to rebuild and expand our Nuclear power generation by switching to Thorium.

The need to develop Thorium based Nuclear Energy as the major electric energy supply. 11. Atmospheric pressure operating conditions, no risk for explosions.

 Molten Salt nuclear Reactors operate under Atmospheric pressure  conditions, no risk for explosions. Materials subjected to high radiation tend to get brittle or soften up. Molten Salt Thorium nuclear reactors operate under atmospheric conditions so the choice of materials that can withstand both high temperatures and high radiation is much greater, leading to a superior and less expensive design.  There is no high pressure gas buildup and the separation stage can be greatly simplified.

The need to develop Thorium based Nuclear Energy as the major electric energy supply. 9. Molten Salt Thorium Reactors cannot have a meltdown, the fuel is already molten.

With Molten Salt nuclear Reactors there is no risk for a meltdown, the fuel is already molten, and that is a safe design. The fissile fuel in a Thorium reactor is U-233 in the form of UraniumFluoride (UF4) salt which also contains Lithium and Beryllium. In its molten form it has a very low vapor pressure. The salt flows easily through the heat exchangers and the separators. The salt is very toxic, but it is completely sealed. Being a fluid, it is constantly mixed for optimum efficiency. The reactor will never have to be shut down for refueling, it is a continuous flow process. Uranium-235 Nuclear reactors on the other hand have to be shut down for refueling and rebalancing of the fuel rods a little more often than once every two years. The average shutdown is 35 days, or about 5% of the time. Then comes the major problem of safely and securely transporting and reprocessing the spent fuel.

The need to develop Thorium based Nuclear Energy as the major electric energy supply. 8. Molten Salt Thorium Reactors are earthquake safe.

Molten Salt Thorium Reactors are earthquake safe. Thorium reactors have a very simple and compact design where gravity is the only thing needed to stop the nuclear reaction. Conventional nuclear reactors depend on external power to shut down after a SCRAM, where poison rods fall down to halt the reaction.  The next figure shows the concept of a Thorium reactor.

The idea is to empty the fissile U-233 core through gravity alone. All that is needed is a melt-plug that is constantly cooled by cold air. In an earthquake the cold air flow automatically shuts off, and since the fuel is already molten, it will then run down into channels like pig-iron into cooling heat exchangers with  water supplied through gravity alone.

As we can see the reactor hardened structure is compact, and can be completely earthquake and tsunami proof. What can be sheared off are the steam pipes and external power, but the reactor shutdown will complete safely without additional power, even if the earthquake is so bad the reactor is broken into pieces.

The need to develop Thorium based Nuclear Energy as the major electric energy supply. 7. Produces isotopes that helps cure certain cancers.

Produces isotopes that helps cure certain cancers. For decades, medical researchers have sought treatments for cancer. Now, Alpha Particle Immunotherapy offers a promising treatment for many forms of cancer, and perhaps a cure. Unfortunately, the most promising alpha-emitting medical isotopes, actinium-225 and its daughter, bismuth-213, are not available in sufficient quantity to support current research, much less therapeutic use. In fact, there are only three sources in the world that largely “milk” these isotopes from less than 2 grams of thorium source material. Additional supplies were not forthcoming. Fortunately, scientists and engineers at Idaho National Laboratory identified 40-year-old reactor fuel stored at the lab as a substantial untapped resource and developed Medical Actinium for Therapeutic Treatment, or MATT, which consists of two innovative processes (MATT-CAR and MATT-BAR) to recover this valuable medical isotope.

The need to develop Thorium based Nuclear Energy as the major electric energy supply. 6. Thorium based nuclear power is not suited for making nuclear bombs.

 Thorium based Nuclear Power does not produce Plutonium239, which is the preferred material used in nuclear bombs. The higher Plutonium isotopes and other TRansUraniums are about as nasty as they get, and 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 PU-238, 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 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 need were developed the greatest asset of nuclear power became its greatest liability.

 

The need to develop Thorium based Nuclear Energy as the major electric energy supply. 5. Radioactive waste from an LFTR decays down to background radiation in 300 years compared to a million years for U-235 based reactors.

 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.

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.