How does a nuclear reactor work? Principle??

Nuclear energy is the energy released from the nucleus by converting its mass, in accordance with Albert Einstein's equation e=mc, where e=energy, m=mass, and c=light speed constant. Nuclear energy is released through one of three nuclear reactions:

Nuclear fission, which opens the binding force of the nucleus.

Nuclear fusion, where particles of atoms are fused together.

Nuclear decay, a naturally much slower form of fission.

Categories: Science & Engineering >> Engineering & Technology Sciences.

Problem description: I understand it in an easy-to-understand way, don't give me an article**!

Analysis: A nuclear reactor, also known as an atomic reactor or reactor, is a device that uses loaded nuclear fuel to maintain and control large-scale chain fission reactions, and continuously brings out the fission energy to do work, and realizes the conversion of nuclear energy to thermal energy.

The structural forms of nuclear reactors are varied, and various types of reactors can be built according to the form of fuel, the type of coolant, the form of neutron energy distribution, and the special design needs of the reactor. According to the different fuel types, nuclear reactors can be divided into natural gas uranium reactors, enriched uranium reactors, and thorium reactors; According to different uses, it can be divided into several types, such as research reactors, production reactors and power reactors; According to the different coolant (heat carrier) materials, it can be divided into water-cooled reactors, gas-cooled reactors, organic liquid-cooled reactors and liquid metal cold reactors; According to the different moderators (moderators), they can be divided into graphite reactors, heavy water reactors, pressurized water reactors, boiling water reactors, organic reactors, molten salt reactors and beryllium reactors, etc. Although there are more than 900 conceptual designs for nuclear reactors, they are currently very limited in practical use.

For a long time to come, nuclear energy will become an important pillar of the human energy industry, and people can use nuclear reactors for peaceful purposes. The DPRK nuclear issue and the Iranian nuclear issue, which the international community is now concerned about, are in fact a continuation of the Cold War confrontation and are in essence a political issue, and only peaceful consultations are the only way to resolve this issue.

1. A nuclear reactor, also known as an atomic energy reactor or reactor, is a device that can maintain a self-sustaining chain nuclear fission reaction to realize the utilization of nuclear energy.

2. Through the rational arrangement of nuclear fuel, the nuclear reactor can carry out the self-sustaining chain nuclear fission process in it without the need to add a neutron source. Strictly speaking, the term reactor should cover fission reactors, fusion reactors, and fission fusion hybrid reactors, but generally only fission reactors.

3. During the Manhattan Lease and Lift Project, the first nuclear reactor was built in December 1942 by a team led by the famous American-Italian physicist Enriko Fermi, named Chicago No. 1 (Chicago Pile-1). The reactor uses a uranium fission chain reaction, which ushered in the era of human atomic energy, and the University of Chicago has become the "birthplace of atomic energy" for mankind.

A nuclear reactor is a device that can maintain and control the nuclear fission chain reaction, thereby realizing the conversion of nuclear energy to thermal energy. The nuclear reactor is the heart of the nuclear power plant, in which the nuclear fission chain reaction takes place.

In 1942, the University of Chicago built the world's first self-sustaining chain reactor, which opened a new era of nuclear energy utilization.

The reactor consists of a core, a cooling system, a moderation system, a reflective layer, a control and protection system, a shielding system, and a radiation monitoring system.

Fuel in the core: The fuel for the reactor, not coal or oil, but fissile material. The only material that is naturally occurring in nature that is prone to fission is U-235, which is only found in natural uranium, and the other two isotopes U-238 and U-234 are combined, and the latter two are not easy to fission.

In addition, there are two types of fissile material, U-233 and PU-239, produced by reactors or accelerators.

These fissile materials are used to make metals, metal alloys, oxides, carbides, etc., as fuel for reactors.

Fuel cladding: In order to prevent the escape of fission products, general fuels need to be wrapped in cladding, which are made of aluminum, zirconium alloy and stainless steel.

Control rods and safety rods in control and protection systems: In order to control the rate of the chain reaction at a predetermined level, the absorption rods need to be made of neutron-absorbing materials, which are called control rods and safety rods. Control rods are used to compensate for fuel consumption and regulate the reaction rate; The safety rod is used to quickly stop the chain reaction.

The absorber materials are generally boron, boron carbide, cadmium, silver indium cadmium, etc. Coolant in the cooling system: In order to remove the heat from fission, the reactor must have a coolant, and the commonly used coolants are light water, heavy water, helium and liquid metal sodium.

Moderator in the moderation system: Because slow neutrons are more likely to cause uranium-235 fission, and neutron fission is fast neutrons, so some reactors need to put materials that can slow down neutrons, which are called moderators, and generally moderators include water, heavy water, graphite, etc.

Reflective layer: The reflective layer is located around the active zone, which can be heavy water, light water, beryllium, graphite or other materials. It reflects the neutrons escaping from the active zone, reducing the amount of neutron leakage.

Shielding system: A shielding layer is set around the reactor to reduce neutrons and doses.

Radiation monitoring system: This system monitors and detects radioactive leaks at an early stage.

Systems and facilities that convert nuclear energy released by the fission of atomic nuclei into heat and then into electrical energy are commonly referred to as nuclear power plants. It is composed of "boilers", generator sets and other control, transmission and distribution and other related auxiliary facilities similar to ordinary thermal power plants. But its "boiler" is not an ordinary boiler, but an "atomic boiler", often called a nuclear reactor.

Due to the different types of nuclear reactors, the systems and equipment of nuclear power plants are also different. The following is an example of a pressurized water reactor to introduce the working principle of a nuclear power plant.