Why Molten Salt Reactors and Thorium Are Nuclear Power’s Answer to Solve Our Energy Future and Hush Criticism
Nuclear energy is at the center of the debate caused by the need to shape a future in which we are able to give a firm response to our energy needs minimizing the emission of greenhouse gases.
Some countries, such as Spain or Germany, have opted for take it out of the equation programming the gradual shutdown of all its nuclear power plants, but for others, such as the United States, China, India or France, nuclear energy is, and it seems that it will continue to be in the long term, an essential part of their energy system.
Renewable energies are the other great focus of attention in the challenge that we all have before us. The medium and long-term strategy of the countries that have opted to shut down their nuclear power plants consists of solving most of their energy demand resorting to themBut this does not mean that states that maintain their confidence in nuclear energy will not also rely on renewables.
China is about to start testing an experimental molten salt nuclear reactor that will use thorium as its main fuel.
In fact, the United States and China, which occupy the first and third positions respectively in the ranking that lists the countries with the most nuclear reactors on the planet (among them only France is holding the pulse), defend an energy model in which renewables will be protagonists and will be backed by nuclear power.
Precisely, this gigantic Asian country (giant both in size and, above all, by its population volume) he’s stepping on the gas as far as the development of nuclear power is concerned, and it will probably not take many years to have more nuclear reactors than the United States. However, and this is the really interesting thing, China is not just doing more of the same; It is devoting many financial, technical and scientific resources to the development of fourth generation nuclear reactors.
And, apparently, he is doing well. At least well enough to find yourself about to start testing an experimental molten salt reactor nuclear reactor that it will use thorium as its main fuel, a chemical element that is more abundant on our planet than the uranium used as fuel in current nuclear power plants, and which, in addition, according to experts, enables safer facilities to be set up. However, these are by no means the only interesting features of molten salt reactors like the one China is about to launch.
Molten salt and thorium reactors, the great asset of nuclear energy
During the conversation I had at the end of last April with Alfredo García, better known on Twitter for his alter ego @Nuclear Operator, I did not miss the opportunity to ask this expert his opinion about the role thorium aspires to play in nuclear energy in the medium and long term. The response from Alfredo, who currently works as an operations supervisor in the control room of the Ascó nuclear power plant, in Tarragona, was very revealing:
«What makes it attractive is that there are three to four times more thorium than uranium on Earth. This does not mean that we will run out of uranium now. According to NEA, which is the Nuclear Energy Agency of the OECD (Organization for Economic Cooperation and Development), we have reserves at the current price and sustaining current consumption for 135 years. It is possible that we will have more reserves at higher prices, and also that new reserves will be discovered elsewhere, so we will not run out of uranium for the next few decades.
“Thorium is as easy to extract as uranium, but it has the disadvantage that not directly fissile. It is necessary to introduce it into a reactor that makes uranium from thorium, and what it produces is not uranium-235, it is uranium-233, but the important thing is that it is fissile. Once this uranium has been produced, it can be introduced into a conventional reactor like the ones we have in Spain, which could not work with thorium, but with a derivative of that element. India is working hard with this resource because it is building new nuclear power plants, and it also has huge reserves of thorium. China also has significant thorium deposits, “says Alfredo.
When this technician spoke these words, he knew very well what he was up to, and he did not mention China in a gratuitous way. The experimental molten salt nuclear reactor that this country is about to test, known by the technical name TMSR-LF1, is located in the Minqin industrial complex of Gansu province, north China. It has a power of 2 megawatts thermal (MWt), and, although it will not be the first active fourth-generation nuclear reactor, and not the first to use thorium as fuel, it will be the first molten-salt reactor to use this chemical element.
If you want to know in some detail How does a Nuclear Center work I suggest you take a look at the report in which we explain it in great depth. In this article we are only going to investigate the characteristics why molten salt reactors are interesting and represent an important asset for nuclear energy in the short and medium term. The most obvious advantage of the Chinese TMSR-LF1 reactor is that it uses thorium, and, as we have seen, it is a more abundant chemical element than uranium, which will presumably lower the cost of refueling.
In addition, experts assure that molten salt nuclear reactors are safer than the reactors installed in nuclear power plants that are currently in operation. Two of the reasons are that lithium and beryllium fluoride salts are used as coolant at very low pressure, and fuel remains dissolved in the form of salt, so it is highly unlikely that an accident could trigger the meltdown of the reactor core. Another quality of these reactors that we should not overlook is that their architecture allows them to be installed underground, which, again, increases their safety.
Radioactive waste generated by thorium molten salt reactors has a much shorter half-life
But this is not all. Another peculiar and positive characteristic of these reactors is that they allow to recharge the fuel while they are kept in operation. And, in addition, the fact that they do not need water to keep the core cool allows them to be installed in regions where water is scarce, or, simply, in areas where there is no river and are not close to the sea. This is one of the reasons why, precisely, China is investing in the development of this technology as a means to build fourth-generation nuclear power plants in the most remote and arid regions of the country.
More important advantages of these reactors. The radioactive waste they generate has a half-life much shorter than that of the waste from reactors that use uranium, which, logically, facilitates its management. And furthermore, molten salt reactors use less fuel because the efficiency of thorium is much higher than that of uranium. Virtually all fuel is involved in nuclear fission, so its use, in theory, is maximum.
There are other technology-based reasons why the Chinese TMSR-LF1 reactor is extraordinarily promising from both a safety and an efficiency point of view, but what we have reviewed in this article gives us a pretty good idea of the reasons why it is so important. Even so, it must still show that everything the theory tells us manifests itself in practice. If it does, countries that still believe in nuclear power will have an option within their grasp that promises us to be safer, more efficient and more environmentally friendly.
Imágenes | Foro Nuclear | US Department of Energy Nuclear Energy Research Advisory Committee