The need to develop Thorium based Nuclear Energy as the major electric energy supply. 14. No need for evacuation zones, can be placed near urban areas.

No need for evacuation zones, can be placed near urban areas. Molten Salt Thorium reactors operate at atmospheric pressure and have a very high negative temperature coefficient, so there is no risk for a boil-over. They are easily made earthquake-safe and no pressure vessel is needed. This will greatly simplify the approval process, no need for elaborate evacuation plans have to be developed. Since the Three Mile Island accident there was a thirty year gap in approvals for new nuclear plants. The “not in my backyard ” mentality reigned supreme, and delay and denial was the rule of the years. But the lawyers still got their share, leading to escalating cost for new nuclear power. In the early days of nuclear power France took the approach of building some of their nuclear plants near the Belgian and German border, so they only had to develop half of an  evacuation plan, leaving the other half to their understanding neighbors. It also leads to placing the nuclear plants where there is the least resistance, not where they are needed the most, adding to the strain on the electric grid.

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. 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. 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.

China is seriously considering restricting rare earth exports to the US. Why is that important?

One week ago, President Xi and Vice Premier Liu He, China’s top trade negotiator, visited a rare earth metals mine in Jiangxi province. This has led to the rumor that China is seriously considering restricting rare earth exports to the US. China may also take other countermeasures in the future. The trade negotiations between U.S. and China got a lot more serious. It extends far beyond tariffs and intellectual property, it now involves strategic materials.

The first thing we must realize is that rare earth metals are not all that rare. They are a thousand times or more abundant than gold or platinum in the earth crust and easy to mine, but a little more difficult to refine. Thorium and Uranium will  also be mined at the same time as the rare earth metals since they appear together in the ore.

Related image

U.S. used to be the major supplier of rare earth metals, which was fine up to around 1984. Then the U.S. regulators determined that Uranium and Thorium contained in the ore made the ore radioactive, so they decided to make rare earth metal ore subject to nuclear regulations with all what that meant for record keeping and control. This made mining in the U.S. unprofitable so in 2001 the last domestic mine closed down. China had no such scruples, such as human and environmental concerns, so they took over the rare earth metals mining and in 2010 controlled over 95% of the world supply, which was according to their long term plan of controlling the world by 2025.

Rare Earth Element Production

The U.S. used to have a strategic reserve of rare earth metals, but that was sold off in 1998 as being no longer cost effective or necessary. Two years later the one U.S. rare earth metals mine that used to supply nearly the whole world, the Mountain Pass Mine in California closed down, together with its refining capacity. From that day all rare earth metals were imported. In 2010 it started up again together with the refining capacity but went bankrupt in 2015, closed down the refining but continued selling ore to China. They just announced they will start up refining again late 2020. Meanwhile China is slapping on a 25% import tariff on imported ore starting July 1. Rare earth metals may be in short supply for a while.

So, why is this important? Just take a look at all the uses for rare earth metals. The most sought after pays all the cost of mining and refining, and the rest are readily available at nominal cost.

The Chinese almost got away with it, and that is but one reason the trade negotiations are so complicated and hard fought, but necessary. Donald Trump fights for reciprocity and fair competition.

The need to develop Thorium based Nuclear Energy as the major electric energy supply. 3. One ten-thousandth of the TRansUranium waste compared to a U-235 based fast breeder reactor.

 A Thorium based fast breeder nucear reactor produces much less TRansUranium waste, 0.01% waste products compared to a Uranium-235 fast breeder. The Thorium process has a much higher efficiency of fission than  the Uranium process. See the figure below.

Pu = Plutonium, Am = Americum, Cm = Curium, all TRansUraniums, nasty stuff.

With Thorium based Nuclear power, there are no real problems, with traditional U235 power long tern storage is an immense and urgent problem, and has been since the 1960’s. At that time Sweden had a heavy water  U-238 nuclear power program going, but abandoned it in favor of traditional U-235 power. U.S. promised to provide the material and take care of the reprocessing and final storage of all nuclear waste at cost if Sweden joined the nuclear proliferation treaty. Reprocessing was to be done in Washington State, and one of the final storage sites mentioned was Yucca Mountain in Nevada, having the ideal Geological properties.

Time goes by and in 1982 – Congress passed the Nuclear Waste Policy Act, requiring the establishment of a deep geologic repository for nuclear waste storage and isolation. Yucca Mountain was high on the list out of of 9 possible sites.

Time goes by, and Congress is still not able to decide on a solution. Meanwhile, TRU’s from spent and reprocessed fuel is piling up in less than ideal locations. Thorium based nuclear power would go a long way to alleviate this problem.