Nuclear energy

Nuclear energy. It is the energy produced by atomic reactions of fusion (union of very light atomic nuclei) or fission (division of heavy atomic nuclei). It can be released spontaneously or artificially in nuclear reactions. Said energy can be used to obtain Electric , mechanical or thermal Energy . The concept, therefore, is often used to name both the outcome of nuclear reaction and the knowledge, techniques and technologies linked to the use of such energy.

Summary

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  • 1 History of nuclear energy
  • 2 Advantages of nuclear energy
  • 3 Use of nuclear energy
    • 1 The isotopic tracing in biology and medicine
    • 2 Radiation and radiotherapy
    • 3 The different forms of radiotherapy
    • 4 Sterilization
    • 5 The elaboration of materials
    • 6 Industrial radiography X og
    • 7 Leak detectors and level indicators
    • 8 Fire detectors
    • 9 Luminescent paints
    • 10 The power supply of the satellites
    • 11 Electricity production
    • 12 The nuclear fuel cycle
    • 13 nuclear medicine
      • 13.1 Examples of explorations
    • 4 See also
    • 5 Sources

History of nuclear energy

Henri Becquerel

In 1896 Henri Becquerel discovered that some chemical elements emit radiation. He and Marie Curie and others studied their properties, discovering that these radiations were different from the already known X-rays and that they had different properties, naming the three types that managed to discover alpha, beta and gamma.

All of them were soon seen to come from the atomic nucleus that Rutherford described in 1911 .

During the 1930s , Enrico Fermi and his collaborators bombarded more than 60 elements, including 235U, with neutrons, producing the first artificial nuclear fissions. In 1938 , in Germany , Lise Meitner , Otto Hahn and Fritz Strassmann verified Fermi’s experiments and in 1939 they demonstrated that part of the products that appeared when carrying out these experiments with uranium were barium nuclei . Very soon they concluded that they were the result of the division of the uranium nuclei. The discovery of fission had been carried out. InFrance , Joliot Curie discovered that in addition to barium, secondary neutrons were emitted in that reaction, making the chain reaction feasible.

During World War II , the Nazi German Armaments Development Department developed a nuclear power project (Project Uranium) with a view to the production of a nuclear explosive device. Albert Einstein , in 1939 , signed a letter to President Franklin Delano Roosevelt of the United States , written by Leó Szilárd, warning of this fact.

The 2 of December of 1942 as part of the Manhattan project led by J. Robert Oppenheimer, the first reactor of the world made by humans (there was a natural reactor at Oklo) was built: the Chicago Pile-1 (CP-1) .

As part of the same military program, a much larger reactor was built at Hanford, for the production of plutonium, and at the same time, a cascade uranium enrichment project. The 16 of July of 1945 was tested the first nuclear bomb (codename Trinity) in the desert of Alamogordo. In this test, an explosion equivalent to 19,000,000 kg of TNT (19 kilotons) was carried out, a power never seen before in any other explosive. Both projects developed ended with the construction of two bombs, one enriched uranium and one plutonium (Little Boy and Fat Man) that were dropped on the Japanese cities of Hiroshima August 6 , 1945 and Nagasaki August 9from 1945 respectively. The 15 of August of 1945 ended World War II in the Pacific with Japan’s surrender. For its part, the German nuclear weapons program (led by Werner Heisenberg), did not reach its goal before the surrender of Germany on May 8 , 1945 .

Later they conducted nuclear programs in the Soviet Union (first test of a fission bomb the 29 of August of 1949 ), France and Britain , starting an arms race in both blocks created after the war, reaching limits destructive power ever previously suspected by the human being (each side could defeat and destroy all its enemies several times).

Currently nuclear weapons do not have an important role in the world and on the contrary what is sought to clean the planet of this type of explosives that damage ecosystems and the environment, on the contrary they are used in the branches of medicine, research , the generation of electricity, the space race among many other uses.

Advantages of nuclear energy

Nuclear power generates one third of the electricity produced in the European Union , thus avoiding the emission of 700 million tons of dioxide carbon per year to the atmosphere .
Nuclear power can prevent many of the environmental consequences that come from the use of fossil fuels . A very important advantage of nuclear energy is that it avoids a wide spectrum of problems that appear when burning fossil fuels ( Coal , Oil or Gas ). Those problems probably exceed those caused by other human activity. One of them and which has received special attention is theGlobal Warming , which is responsible for changing the planet’s climate; so-called acid rains, which destroy blocks and kill tens of thousands of people each year.
An additional advantage of nuclear power is the nature of the fuel consumed. Oil and gas are the primary sources for heating and transportation and will be difficult to replace for those applications. So there are many reasons to keep our fossil fuel reserves. UraniumIt is a nuclear fuel, which on the other hand, has no other uses than that of using it as a source of energy generation. The Uranium reserves available together with the uses of the reproductive reactors would allow supplying humanity for billions of years in the energy supply without altering the cost of the generation of energy produced that in quantities of the order of 1% due to variations in Uranium cost. For these reasons it is always better to use renewable energy sources that are less polluting and less dangerous to health.

Use of nuclear energy

 Isotopic tracing in biology and medicine

Electro-nuclear plant

Different isotopes of an element have the same chemical properties. The replacement of one by the other in a molecule does not modify, therefore, its function. However, the radiation emitted allows it to be detected, located, tracked and even dosed at a distance. The isotopic tracing has made it possible to study, without disturbing it, the functioning of everything that has life, from the cell to the entire organism. In Biology , numerous advances made during the second half of the 20th centuryThey are linked to the use of radioactivity: genome function (inheritance support), cell metabolism, photosynthesis, transmission of chemical messages (hormones, neurotransmitters) in the body. Radioactive isotopes are used in nuclear medicine, mainly in medical imaging, to study the mode of action of drugs, understand how the brain works, detect a cardiac abnormality, discover cancer metastases.

Radiation and radiotherapy

Ionizing radiation can preferentially destroy tumor cells and is an effective cancer treatment, radiotherapy, which was one of the first applications of the discovery of radioactivity. In France, between 40 and 50% of cancers are treated by radiation therapy, often associated with chemotherapy or surgery. Radioactivity allows a large number of people to be cured each year.

The different forms of radiotherapy

Curiotherapy uses small radioactive sources (platinum-iridium threads, cesium grains) placed near the tumor. The tele radiotherapy, consists of concentrating in the tumors the radiation emitted by an external source. Immunoradiotherapy uses radiolabeled vectors whose isotopes specifically recognize the tumors they are attached to in order to destroy them.

Sterilization

Irradiation is a privileged means of cold-destroying microorganisms: fungi, bacteria, viruses … For this reason, there are numerous applications for the sterilization of objects, especially for medical-surgical material. Protection of works of art Gamma-ray treatment allows the removal of fungi, larvae, insects or bacteria found inside objects in order to protect them from degradation. This technique is used in the treatment of conservation and restoration of objects of art, ethnology, archeology.

Materials development

Irradiation causes, under certain conditions, chemical reactions that allow the production of lighter and more resistant materials, such as insulators, electrical cables, thermo retractable envelopes, prostheses, etc.

Industrial radiography X og

It consists of recording the image of the disturbance of an X-ray beam caused by an object. It allows to locate the faults, for example, in the welds, without destroying the materials.

Leak detectors and level indicators

The introduction of a radio element in a circuit allows to follow the movements of a fluid, detect leaks in dams or underground pipes. The level of a liquid inside a tank, the thickness of a sheet or cardboard in the process of being manufactured, the density of a chemical inside a tank … can be known using radioactive indicators.

Fire detectors

A small radioactive source ionizes the oxygen and nitrogen atoms contained in a small volume of air. The arrival of smoke particles modifies this ionization. For this reason, radioactive detectors sensitive to very small amounts of smoke are made and used in shops, factories, offices …

Luminescent paints

These are the oldest applications of radioactivity for reading the dials of clocks and dashboards for night driving.

The power supply of the satellites

The electrical batteries work thanks to small radioactive sources with plutonium 239, cobalt 60 or strontium 90. These batteries are mounted on satellites for their energy supply. They are very small in size and can function without any maintenance for years.

Electricity production

Diagram of the operation of an Electro-nuclear plant

Fission chain reactions of uranium are used in nuclear power plants, which in France produce more than 75% of electricity.

The nuclear fuel cycle

In a reactor, the fission of uranium 235 causes the formation of radioactive nuclei called fission products. Neutron capture by uranium 238 produces some plutonium 239 which can also provide energy by fission. Only a tiny part of the fuel placed in a reactor is burned in the fission of the nucleus. The fuel that has not been consumed and the plutonium formed are recovered and recycled to produce electricity again. The other elements formed in the course of the reaction are classified into three categories of waste according to their activity, to be packed and then stored.

Nuclear medicine

Nuclear medicine is a specialty of today’s medicine. Radiotracers or radiopharmaceuticals are used in nuclear medicine. They are made up of a transporter drug and a radioactive isotope. These radiopharmaceuticals are applied within the human body through various routes (the most widely used is the intravenous route). Once the radiopharmaceutical is inside the body, it is distributed by various organs depending on the type of radiopharmaceutical used. The distribution of the radiopharmaceutical is detected by a radiation detection apparatus called a gamma camera and stored digitally. The information is then processed, obtaining images of the entire body or organ under study. These images, unlike most of those obtained in radiology, are functional and molecular images, that is, they show how the organs and tissues explored are functioning or reveal alterations of them at a molecular level. Nuclear medicine examinations are generally noninvasive and without adverse effects.

Examples of explorations

  • Kidney scan — Used to examine the morphology and function of the kidneys to detect any abnormalities, such as infections or obstruction of urinary flow.
  • Thyroid scan — Used to assess thyroid morphology and function, especially in hyperthyroidism.
  • Bone scintigraphy: used to evaluate bone and joint diseases, whether they are of a tumor, inflammatory, degenerative, traumatic, metabolic or vascular origin.
  • Gallium-67 (Ga-67) scan: Used to diagnose active inflammatory or infectious diseases, tumors, and abscesses.
  • Myocardial Perfusion SPECT: Used for the diagnosis of coronary heart disease and to assess its prognosis and the state of cardiac function.
  • Brain Perfusion SPECT – Used to investigate dementia, epilepsy, vascular brain disease, and brain tumors.
  • PET-CT: uses positron-emitting isotopes for the diagnosis and monitoring of tumors, brain and cardiac diseases.
  • Radio-directed surgery: Radiopharmaceuticals designed to detect and remove tissues intraoperatively are used.
  • Radioisotope treatments: Treatment of hyperthyroidism and thyroid cancer with Iodo-131 (I-131). Treatment of metastatic bone pain with Samarium-153 (Sm-153).

 

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