Without using the conventional enriched uranium fuel rod, liquid
Molten salt Into
thorium A liquid fuel mixed with a fissionable substance
Thorium molten salt furnace Has been proposed as an energy source with less radioactive waste and a high level of safety over 50 years ago. However, various problems have been found and it has not come true yet, but NRG (The Nuclear Research & Consultancy Group), a nuclear research company based in the Netherlands, uses actual facilities We have started demonstration experiments.
Thorium is a natural element that can power the world for millenniums to come! You can hold your entire life's energy supply in the palm of your hand with thorium!
Thorium molten salt nuclear reactor (TMSR) is a nuclear reactor that uses thorium molten salt containing fissile material as both fuel and coolant. A tunnel of "graphite reflective material" that reflects neutrons is installed in the nuclear reactor, and thorium molten salt liquefied is pumped by the power of the pump into the tunnel. When passing through the tunnel of the reflective material, the fissile material contained in the thorium molten salt undergoes a fission reaction and generates enormous heat. Thorium molten salt causes the generated thermal energy to be transferred as it is to the heat exchanger as a coolant, and generates steam to rotate the turbine to generate electricity.
Nuclear power plants currently operating around the world use "pellets" that solidify uranium as fuel as solid nuclear fuel. However, due to its principle, pellets can not completely use up fuel and unreacted nuclear material is left. This is the main radioactive waste, that is, "nuclear waste", but now that the fast breeder reactor plan has been torn down, nuclear waste has lost its place and world countries are plagued by disposal.
The TMRS that does not use this pellet is much smaller than the conventional nuclear power generation radioactive material which becomes waste, and it has the energy source of "next generation nuclear power generation of dream" which has constant self-stability capability even when accident happens The concept has been advocated for more than 50 years ago. In the 1960s research at the Oak Ridge National Laboratory in the United States of America advanced and nuclear reactor design was done, but actual construction was not done.
It is the NRG that started the experiment to actually build and operate this TMRS. The project named SALIENT (SALt Irradiation ExperimeNT) is composed of two stages, SALIENTE - 1 and SALIENTE - 2. In SALIENTE-1, experiments using a mixture of lithium fluoride (LiF) and thorium fluoride (ThF 4) are carried out. Place LiF / ThF in a concentric metal tube with a height of 50 cm, put it in a high neutron flux oven and irradiate it with neutrons. Then thorium reacts and changes to uranium and starts nuclear fission. At that stage, I will verify whether or not the theoretical reaction will be carried out by putting sponge-like substance or thin film made of nickel and confirming that precious metal to be byproduct of fission will adhere to its surface.
Next, in SALIENTE-2, experiments using a fluoride molten salt containing beryllium "FliBe" which is generally assumed in a molten salt type nuclear reactor will be conducted. Here, in addition to investigating the state of reaction of the contents in more detail, the influence of molten salt with high corrosiveness will also be investigated. In general, molten salt has been considered to be difficult to put into practical use because it gives a strong damage to the metal of piping, but it is supposed to be verified whether introducing new materials can clear this problem I will.
Thorium molten salt nuclear reactors are attracting worldwide attention as nuclear reactors with less environmental impact. Development is proceeding even in China where energy distress due to future population increase is concerned, and similar research is being carried out in India and Indonesia.
Spotlight on "Thorium" rushing development of next generation nuclear reactors in China: Nihon Keizai Shimbun
Meanwhile, there are voices showing skeptical views on its feasibility and principle. As mentioned above, there are concerns about problems such as high corrosivity and extremely strong gamma waves released at the stage of processing.
Thorium molten salt furnace is impossible during this century - BB 45 _ Colorado's commentary - Togetter Summary
At NRG, we are aiming for the leadership of energy development in the future by pioneering TMRS earlier.
Source : https://gigazine.net/gsc_news/en/20170824-salient/