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In recent years, environmental pollution and carbon emissions caused by fossil fuels have led to faster development of nuclear energy. But with the increasing demand for the safety of nuclear power systems following the Fukushima accident in Japan, a new generation of nuclear power systems has been developed on the basis of the third generation. The materials used in the new generation nuclear power system need to have better mechanical properties, thermophysical properties, strong radiation resistance, corrosion resistance, and thermal shock resistance. Therefore, it is urgent to optimize the existing material system and deeply develop new high-performance materials. Among numerous optional materials, carbide ceramic materials are currently the focus of attention

In order to maintain the rate of fission reaction at a predetermined level, it is necessary to adjust the reaction rate using control rods and safety rods (collectively known as absorption rods). The control rods are used to compensate for fuel consumption and regulate the reaction rate, while the safety rods are used to quickly stop the reaction. The absorbers widely used in light water reactors, heavy water reactors, high-temperature gas-cooled reactors, and fast neutron reactors are mainly boron carbide powder or boron carbide pellets.

The reason for the Fukushima nuclear accident in Japan was the use of zirconium alloy nuclear cladding tubes, which are used in pressurized water reactors. When the temperature rises, hydrogen gas is generated when it meets water at high temperatures, leading to an explosion. Later, the international community developed the use of continuous silicon carbide fiber reinforced silicon carbide ceramic matrix composites as core cladding tubes. This type of pipe with a diameter of 10 millimeters, a length of 4 meters, and a wall thickness of about 1 millimeter is difficult to make, and some domestic manufacturers have taken on this task. 4 meters is very long, and it requires straightness without deformation, and good density because it needs to be filled with nuclear fuel inside. The current international trend is to develop ceramic matrix composites to make core cladding tubes.

Boron carbide has a high melting point, high strength, good corrosion resistance, good neutron absorption performance, stable chemical properties, and as a low atomic number material, it will not release radioactive rays after absorbing neutrons. Therefore, boron carbide material can be applied to the core material of reactor control rods, or boron carbide or boron carbide composite materials can be applied to radiation protection materials.

The component closest to the plasma that undergoes the reaction in a fusion reactor is the first wall. The material of the first wall should have a certain degree of radiation damage resistance. Silicon carbide itself is a low neutron activation material with low neutron radiation induced radioactivity. The silicon carbide composite material has good corrosion and swelling resistance, and as the first wall structural material, it still has sufficient strength at high temperatures and can operate at high temperatures of 800 ℃, Allow the coolant to reach high temperatures, thereby improving the thermal efficiency of the energy system.

Ceramic materials are widely used in the nuclear industry, but some weak links in ceramic materials, such as poor toughness and difficulty in machining, still need to be improved. Currently, ceramic materials such as boron carbide and silicon carbide also have many problems that need to be solved, and their performance needs to be further improved.