Thorium Nuclear Reactors: What Are the Advantages?

The advantages of thorium reactors are numerous:

the 232 Thorium is more abundant than uranium, we can use 100% against a few percent uranium, and there is no need to enrich it.

since 232Th is fertile and non-fissile, it cannot produce a chain reaction. A plant cannot get carried away, and it can shut down on its own in the event of a cooling failure

232Th wastes are dangerous for only a few centuries, compared to hundreds of thousands of years for uranium.

thorium power plants can “incinerate” waste from uranium power plants, including plutonium.

you can’t produce nuclear weapons with a thorium plant.

On the downside, if you look carefully, there are a few, but the main one is: you can’t produce nuclear weapons with a thorium plant. According to Jean-Christophe de Mistral, this is what favored the uranium industry during the Cold War, when several experiments have demonstrated the feasibility and safety of Thorium solutions. Among others:

The experimental reactor at Shipping port in the USA which operated as a Thorium breeder between 1977 and 1982

Several very high temperature reactors (HTGR) operated with fuel rods mixing Uranium 235 and Thorium 232 in the USA, but also in Germany between 1966 and 1989

The experimental reactors and 7 CANDU reactors of 220 MW each using a Uranium / Thorium mix which are currently operating in India. India is the only country that clearly mentions thorium in its energy program, for a simple reason: India has very little Uranium, and cannot easily import it because it has not signed the non-proliferation treaty. On the other hand, it has large deposits of Thorium.

And also, the “Molten-Salt Reactor Experiment” (MSRE) which operated between 1965 and 1969 with various fuels, including Uranium 233 produced from Thorium in another reactor.

From a nuclear point of view, molten salt reactors only have advantages:

the fuel is dissolved in a salt, solid at low temperature, liquid in operation and at the same time serving as primary coolant.

the reaction only occurs in the core because both a source of neutrons and a sufficient volume are needed for the probability of the neutron to be absorbed to be high enough.

the installation operates at ambient pressure: the very high boiling point of the salt prevents the system from becoming a pressure cooker

if the installation overheats, a plug (“Freeze Plug” in the drawing) melts and the salt flows by gravity into reservoirs (in blue) whose geometry stops nuclear reactions. This is also how the MSRE was shut down for maintenance.

The difficulties and unknowns are mainly linked to the chemistry of these salts. A chemical plant needs to be set up to purify them next to the power station, in particular to remove the Xenon 135. It is not clear how an LFTR will age, particularly due to corrosion by salts.

ARE Thorium: no need for tanks anymore, we will also be able to put passengers in the wings …

In passing, I discovered the existence of the Aircraft Reactor Experiment project which targeted the nuclear propulsion of planes. It was an MSR whose salts at 850 ° heated the air in the reactors, which operated for 1000 hours in 1954, when we were afraid of nothing except maybe red ones. So, I didn’t know it, but yes, there is an alternative to the turbojet in the boxes.

The book “The Green Atom” is very interesting and convincing for the insider, but it sometimes seemed too technical for the general public. I also find it unnecessarily provocative for diehard ecologists, in particular the passage comparing the risks of various energy sources per TWh produced and the one comparing cancer rates in areas with high natural radioactivity, even if it is very interesting.

Finally, even the conclusion seems too thick to me for ordinary politicians who are nevertheless the people to convince, so I summarize for them: “Thorium to be able to produce clean and cheap Terawatts to replace oil and coal. You have to give the green light; we take care of the rest”. I don’t know what that sounds like in Hindi or Mandarin, but there they understood.

Stalwart International – One of the best Chemical reactor manufacturer in Ankleshwar.