Everything in the world is made up of atoms, and atoms are made up of nuclei and their surrounding electrons.

Both the fusion of light nuclei and the division of heavy nuclei can release energy, which is called nuclear fusion energy and nuclear fission energy, or nuclear energy for short. The nuclear energy mentioned here refers to nuclear fission energy.

The fuel of the aforementioned nuclear power plant is uranium. Uranium is a heavy metal element, and natural uranium consists of three isotopes: uranium -235 0.7 1%, uranium -238 99.28%, and uranium -234 0.0058% (uranium -235 is the only nuclide easy to fission in nature. )

When a neutron bombards the uranium -235 nucleus, the nucleus can split into two lighter nuclei, producing two or three neutrons and rays at the same time, and releasing energy. If the newly generated neutron hits another uranium -235 nucleus, it can cause new fission.

In the chain reaction, energy will be released continuously. How much energy is released from uranium -235 fission? Please remember a number, that is, the energy released by 1 kg uranium -235 is equivalent to the energy released by burning 2700 tons of standard coal.

Reactor is the key design of nuclear power plant, and the chain reaction of nuclear fission is among them. There are many kinds of reactors, among which pressurized water reactor is the most widely used one in nuclear power plants.

There must be nuclear fuel in the pressurized water reactor first. The nuclear fuel is to put the sintered uranium dioxide pellets with the size of little finger into zirconium alloy tubes, and assemble more than 300 zirconium alloy tubes with the pellets to form a fuel assembly.

Most components have a bundle of control rods to control the intensity of chain reaction and the start and end of the reaction. PWR uses water as coolant, flows through the fuel assembly driven by the main pump, absorbs the heat energy generated by nuclear fission, then flows out of the reactor and enters the steam generator, where it transfers the heat to the water on the secondary side, making them turn into steam and send it to power generation, and at the same time, the temperature of the main coolant itself is reduced.

The main pump sends the main coolant in the steam generator back to the reactor for heating. This circulating channel of coolant is called the main loop, and the high pressure of the main loop is maintained and adjusted by the voltage regulator.

Coal-fired power stations use coal and oil to generate electricity, hydropower stations use hydropower to generate electricity, and nuclear power stations are new power stations that use the energy contained in atomic nuclei to generate electricity. Nuclear power plants can be roughly divided into two parts: one is a nuclear island that uses nuclear energy to generate steam, including reactor devices and primary loop systems; The other part is a conventional island that uses steam to generate electricity, including a turbine generator system. The fuel used in nuclear power plants is uranium.

Uranium is a heavy metal. Nuclear fuel made of uranium is fissioned in a device called a "reactor" to generate a lot of heat energy, which is carried out by water under high pressure and steam is generated in a steam generator. Steam drives the gas turbine to rotate with the generator, constantly generating electricity and transporting it in all directions through the power grid.

This is the working principle of the most common PWR nuclear power plant. In developed countries, nuclear power has been developed for decades and has become a mature energy source.

China's nuclear industry has a history of more than 40 years. It has established a fairly complete nuclear fuel cycle system from geological exploration and mining to component processing and post-processing. It has built various types of nuclear reactors, has many years of experience in safety management and operation, and has a professional and skilled team. The construction and operation of nuclear power plants is a complex technology.

China has been able to design, build and operate its own nuclear power plants. Qinshan Nuclear Power Station was designed and built by China.

The number of nuclear power plants in Japan is 55 and the proportion of nuclear power is 30%. It is planned to increase the proportion of nuclear power to 4 1% by 2030. There are 20 in India.

Russia has 3 1 nuclear power plants, and the EU has 16 countries, with a total of 158 nuclear power plants. France has 59 seats, Britain has more than 30 seats, and the United States has the most seats, reaching 104.

As far as the proportion of power generation is concerned, there are currently more than 400 nuclear power plants in the world, and their annual power generation accounts for 17% of the world's total power generation. Among them, French nuclear power installed capacity accounts for 78%, Japanese nuclear power installed capacity accounts for 36%, American nuclear power installed capacity accounts for 20%, Korean nuclear power installed capacity accounts for 42%, and Chinese mainland only accounts for 1.6%. China has surpassed the United States to become the largest carbon emitter in the world.

According to the original value, the world has built 1000 nuclear power plants, and 40% of the world depends on nuclear energy. 2500 nuclear power plants can meet the current world electricity consumption. However, under the anti-nuclear movement, the power generation is only 16%. If China builds more than 100 nuclear power plants, it may account for 4%. If there were more than 600 nuclear power plants in China, there would be no energy problem.

Hansen, a former NASA scientist, participated in a study as a co-author. The study estimates that from 197 1 to 2009, the use of nuclear energy may have avoided at least1840,000 people dying from the adverse effects of fossil fuel combustion on a global scale.

They said, "There is no energy system without shortcomings. We hope that when formulating energy system policies, we can be based on facts without feelings and prejudice, because these are not suitable for nuclear energy technology in 2 1 century. "

The development of nuclear energy is very important for medical treatment, environmental protection, military, aircraft carrier, robot power, nuclear-powered satellites, space nuclear-powered aircraft and space station power supply. With the maturity of nuclear batteries in aerospace, aviation, deep-sea robots and other fields, nuclear batteries and solar cells will be applied to automobiles as the main energy source.

Photon transmission technology, a powerful country today, is making this a reality. People fantasize about building a rainbow bridge between the earth and the moon with lasers to exploit the minerals and energy of the moon. The IEA asserts that if the proportion of nuclear power drops sharply in the next few decades, in order to achieve the goal of controlling the concentration of greenhouse gases at 450ppm, emerging low-carbon technologies will need to be strategically deployed and these technologies will need to be verified.

At present, major nuclear power countries also realize that without the participation of nuclear power, it is very difficult and costly to achieve emission reduction targets. Based on the same goal, our recent energy supply needs to focus on the existing nuclear energy and geothermal energy with stable energy.

About 100 years ago, scientists found that some substances can emit three kinds of rays: alpha (alpha) ray, beta (beta) ray and gamma (gamma) ray. Later research proved that α -ray is a stream of α particles (helium nuclei), β -ray is a stream of β particles (electrons), and γ -ray is a stream of photons.

The same characteristics of these rays are: 1,.

2. What are the safety measures for nuclear power plants?

When nuclear fuel "burns", it will produce a lot of radioactive substances.

In order to prevent radioactive materials from escaping, four barriers are usually set up when building nuclear power plants, including fuel pellets, sealed fuel cladding, solid pressure vessel, closed-loop system and containment that can withstand internal pressure. There are also multiple protections in the control of nuclear power plants, such as normal shutdown when there is a situation that may endanger equipment and personal safety; When the reactor cannot be shut down normally, the control rod can automatically fall into the reactor to implement automatic emergency shutdown; If the control rod insertion fails, high-concentration boric acid solution will be automatically injected into the reactor to realize automatic emergency shutdown.

In the design of nuclear power plants, safety is always the primary consideration. Designers will consider possible local natural disasters, such as earthquakes, tsunamis, tropical storms and floods. Even if a serious natural disaster occurs, the reactor should be safely stopped, and the possibility of explosion is very low. So in general, the safety of nuclear power plants is guaranteed.

3. Common sense of nuclear power plants

Nuclear power plant is a system and equipment that converts nuclear energy released by nuclear fission into electric energy. It is usually called a nuclear power station or an atomic power station.

The energy released in the process of nuclear fuel fission is carried out by the coolant circulating in the reactor and transported to the boiler to generate steam to drive the turbine and drive the generator to generate electricity. Nuclear power plant is a kind of power plant with high energy consumption and low material consumption.

Take a power station with a power generation capacity of 6.5438+0 million kilowatts as an example. If you burn coal, you will consume about 7000 ~ 8000 tons of coal every day, more than 2 million tons a year. If it is replaced by a nuclear power plant, it only consumes 1.5 tons of fissile uranium or plutonium every year, and it can run at full power for one year at a time.

It can greatly reduce the transportation and storage problems of power station fuel. In addition, new nuclear fuel can be produced during the combustion of nuclear fuel in the reactor.

Nuclear power plants have high capital investment, but low fuel cost and low power generation cost, which can also reduce pollution. By the end of 1986, 397 nuclear power plants had been built in 28 countries and regions in the world.

According to the statistics of the International Atomic Energy Agency, it is estimated that by the beginning of the 20th century, 58 countries and regions will build nuclear power plants, and the total number of power plants will reach 1 1,000, with an installed capacity of 800 million kilowatts, and nuclear power will account for 35% of the total power generation. Visible, in the future for a long time, nuclear power will become the main energy source of the power industry.

Nuclear energy (1) teaching purpose 1. Understand the common sense of nuclear energy and two ways to release nuclear energy-fission and fusion. 2. Advocate the education of physics research methods.

3. Introduce the achievements of scientists in China and carry out patriotic education. (2) Teaching AIDS: uranium nuclear fission, chain reaction, mushroom cloud wall chart produced after the explosion of atomic bomb and hydrogen bomb, video materials and playing equipment of the first atomic bomb and hydrogen bomb test in China.

(3) Teaching process 1. Introducing a new lesson teacher: In the study of natural radioactivity, scientists found that there is a structure inside the tiny nucleus, and the nucleus can also be changed. In order to study the internal structure of the nucleus, physicists try to bombard the nucleus with particles, first alpha particles, then protons and neutrons. It is found that all of them can cause changes in nuclear-nuclear reactions, and a lot of energy can be released in some nuclear reactions.

We call it nuclear energy because of the huge energy released by nuclear changes. 2. Write a new lesson on the blackboard: (1) What is nuclear energy? Blackboard: