The hottest thorium based molten salt reactor lead

2022-08-11
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Thorium based molten salt reactor leads nuclear energy into a new era

on November 7, the Gansu Provincial People's Government of the Chinese Academy of Sciences signed the strategic cooperation framework agreement between the Chinese Academy of Sciences and the Gansu Provincial People's Government on the thorium based molten salt reactor nuclear power system project

what is the dukey molten salt pile

thorium based molten salt reactor nuclear energy system (tmsr) is one of the six candidates for the fourth generation advanced nuclear energy system, including three subsystems: Thorium based nuclear fuel, molten salt reactor and comprehensive utilization of nuclear energy. It has the characteristics of high inherent safety, less nuclear waste, better non-proliferation performance and economy

among them, molten salt reactor uses high-temperature molten salt as coolant, which has thermal properties such as high temperature, low pressure, high chemical stability and high heat capacity. It does not need to use heavy and expensive pressure vessels, and is suitable for building compact, lightweight and low-cost small modular reactors. In addition, the molten salt pile adopts anhydrous cooling technology, which can operate with only a small amount of water, and can achieve efficient power generation in arid areas. The high-temperature nuclear heat output from molten salt reactors can be used for power generation, industrial thermal applications, high-temperature hydrogen production and hydrogen absorption of carbon dioxide to methanol

a low-key existence

molten salt reactor research and development began in the United States in the late 1940s. Oak Ridge National Laboratory built the liquid fuel molten salt experimental reactor (MSRE) in 1965, which is the only liquid fuel reactor built and operated in the world so far, and also the only reactor that successfully realizes the operation of thorium based nuclear fuel (uranium-233). However, due to the consideration of the "cold war", the plan of molten salt reactor focusing on civil use was dropped, and the research and development of molten salt reactor in the United States was suspended

at the beginning of the 1970s, China also chose thorium based molten salt reactor as the starting point for the development of civil nuclear energy. The zero power cold molten salt reactor was built and reached the critical point in Shanghai "728 project" in 1971. However, limited to the scientific, industrial and economic level at that time, the "728 project" was converted to the construction of light water reactors

in 2011, China restarted thorium based molten salt reactor research. Focusing on the needs of national energy security and sustainable development, the Chinese Academy of Sciences deployed and launched the first batch of the strategic leading science and technology special project of the Chinese Academy of Sciences (Class A) "future advanced nuclear fission energy thorium based molten salt reactor nuclear energy system (tmsr)", which plans to take about 20 years to realize the application of thorium based molten salt reactors in the world, and establish the industrial chain of thorium based molten salt reactors and corresponding scientific and technological teams at the same time

according to the report of world nuclear on September 6, 2017, the experiment of nuclearresearchandconsultancygroup (NRG) will produce new data on the safe operation of molten salt reactor (MSR)

it seems that all this shows that the molten salt pile, which has been interrupted for 40 years, has finally come out of the trough and ushered in the spring of development. We also mainly teach the specific content of the constant speed tensile method to test the tensile strength of paper

the reactor type that was stopped due to the wrong standing in line

nuclear energy always makes some people feel panic. First, more than 95% of the fuel in the traditional uranium based thermonuclear reactor will become nuclear waste, and because it contains transuranic elements, its radiation toxicity cycle will be as long as tens of thousands of years, or even longer. The second is the psychological fear caused by the Chernobyl nuclear accident in 1986 and the Fukushima accident in Japan in 2011. Due to the colorless, tasteless and odorless nature of high-dose ionizing radiation, which kills people invisibly, and the super long half-life of some radioactive elements, these Invisibles have caused a huge psychological shadow to the public

Fukushima nuclear accident site

in view of the above two points, the advantages of molten salt reactors in safety can be seen without comparison:

no enrichment: the final waste is less than half of uranium, and the radiation toxicity cycle is less than 200 years. Therefore, the difficulty of handling nuclear waste will be significantly reduced

molten salt is both fuel and coolant: it has natural negative feedback function. When the reactor temperature is too high, further chain reaction can be stopped

molten salt reactor does not need to be pressurized: because it is liquid, there is no risk of core meltdown

there is no need for a large amount of water as Moderator: the site selection is more free, and it can even be considered to put it underground to reduce the damage caused by leakage accidents to a greater extent

it seems that molten salt piles are all advantages, so why hasn't they been promoted

the centralized research on molten salt reactors originally originated from the usaircraft reactor experiment (are) in early 2018. In 1946, the US air force led the are project, hoping to develop a nuclear powered bomber. But in the end, the rapid development of intercontinental missiles made nuclear powered bombers lose military value. In 1961, the nuclear powered aircraft project was terminated, and the molten salt reactor also lost its strong backing of the military

then, the molten salt pile hugged the civilian father's thigh. In 1965, Oak Ridge laboratory built thorium based molten salt experimental reactor (MSR) based on are, which has been running for 5 years

the good times didn't last long. Affected by the "cold war", the American Atomic Energy Commission (AEC) suddenly cut down the R & D funds of molten salt reactors in the early 1970s, when molten salt reactors entered a mature development period. The molten salt reactors with good performance, clever design and partial civilian use, so the rations were cut off

in 1976, the molten salt reactor project was stopped by the Nixon administration. Later, in addition to the construction of a test reactor in kapakan, India, the relevant research on molten salt reactors gradually fell silent

thorium fuel with more advantages

thorium fuel, a good partner of molten salt reactor, was also defeated in the competition with uranium fuel

at present, there are three commercially valuable fissile elements on earth: uranium-235, uranium-233 and plutonium-239. However, only uranium-235, thorium-232 and uranium-238, which exist in nature, need to absorb fast neutrons to proliferate before fission

compared with uranium, thorium has many advantages

reserve advantage: the proven thorium resources on earth are 3 to 4 times more abundant than uranium (at least). At present, China has more than 280000 tons of thorium ore. Based on the current electricity consumption, the existing thorium resources can support the global electricity consumption for at least a thousand years

reprocessing advantage: Thorium uranium fuel cycle produces much less plutonium and long-lived secondary actinide nuclides

its own characteristic advantages: Thorium and its oxides have the characteristics of radiation resistance, high temperature resistance and high thermal conductivity, so that the reactor can operate at higher temperatures, obtain deeper burnup, that is, produce less nuclear waste

thorium is not suitable for the manufacture of nuclear weapons: it is an ideal civil nuclear fuel and helps prevent nuclear proliferation. Of course, it is also this that leads to its "political correctness"

having said so much, it seems that it is really too excellent. Does thorium have any shortcomings? Of course, there are still some. For example:

although uranium-233 derived from thorium-232 is an excellent fissile material, it also has much higher radioactivity than uranium-235, which will increase the difficulty of making fuel rods

finally ushered in a turnaround

at the beginning of the 21st century, the U.S. Department of energy led the fourth generation reactor International Forum (generationinte now uses plastic waste to make 3D printing consumables rnationalforum, GIF), which put forward higher economic, safety, nuclear waste minimization and non-proliferation requirements for reactors, and screened out six most promising fourth generation candidate reactor types: molten salt reactor (MSR), ultra-high temperature reactor (VHTR) Supercritical water cooled reactor (SCWR), gas cooled fast reactor (GFR), lead cooled fast reactor (LFR) and sodium cooled fast reactor (SFR). The fourth generation reactor system not only includes the research of reactor technology, but also attaches equal importance to the pretreatment and reprocessing of nuclear fuel. Its goal is to develop one or several innovative nuclear power systems by 2030

6 types of reactor, molten salt reactor is the only liquid fuel reactor, so there is no core meltdown (Fukushima nuclear accident) problem. In an emergency, liquid fuel can be discharged into the bottom storage tank

in addition, molten salt can be used as both coolant and fuel, so there is no need to make fuel assemblies, so feeding and post-treatment can be realized, which is convenient for monitoring and management. In addition, because the specific heat capacity of molten salt is higher than that of pressurized water, many materials can be touched by anti household appliances, and the reactor circuit can be designed more compact

based on the above reasons, many scientific research teams have re locked thorium based molten salt reactors:

reaction itself: Thorium based molten salt reactors can form a closed fuel cycle: thorium-232 can be multiplied into uranium-233 to supplement fuel for the reactor, fission products can be separated into usable fuel in the separator, toxic transmutation elements can be removed, and added to molten salt fuel again

material: stainless steel is stable in uranium fluoride and thorium fluoride in molten state and has good compatibility. These two fluorides have very low steam pressure in the molten state, good heat transfer and chemical stability, and the mechanical stress on the reactor structure is small

advantages of historical accumulation: molten salt reactors have successfully operated for 5 years 40 years ago, and have accumulated a lot of experience

principle advantage: the difficulty and technical bottleneck of thorium based molten salt reactor are much smaller than the ultimate energy in everyone's mind - nuclear fusion

since the beginning of this century, the United States, France, Russia, Japan, South Korea, China and other countries have successively launched molten salt reactor research programs

because in the new century, nuclear non-proliferation has become a major constraint to the development of civil nuclear energy, thorium based molten salt reactors cannot be used to produce plutonium, which has become an advantage in the peaceful development and utilization of nuclear energy

at present, Oak Ridge National Laboratory of the United States and China nuclear power are cooperating in the research of thorium based molten salt reactor in Shanghai, and it is expected to build a 100MW liquid fuel thorium based molten salt demonstration reactor in 2035

the Oak Ridge dream of half a century is gradually recast

Alvin, the founder of American nuclear power ˙ In the first nuclear era, inberg wrote:

"in the early stage of nuclear power development, there were various possibilities for the formation of reactors: uranium-233, uranium-235, plutonium-239 as fuel; light water, heavy water, gas, liquid metal as coolant; light water, heavy water, beryllium, graphite as moderator."

in comparison, the "innate advantage" of thorium resources seems to be more suitable for the benefit of mankind. Will the gradually rebuilt dream of "Oak Ridge" lead nuclear energy into a new era

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