In everyday life, nuclear reactions are rarely related to natural phenomena. Most natural phenomena in daily life only involve gravity and electromagnetism. The atomic nucleus consists of positive charges and neutrons, between positive charges d <> natural atomic nucleus arises force repel each other (away from each other), but this can still be held by a force so that the positively charged atomic nuclei do not move away (Binding energy). In 1896, Henri Becquerel examined the phenomenon of phosphorescence in uranium salts which he later called radioactivity. Together with another pair of scientists, Pierre Curie and Marie Curie, they have begun research related to this phenomenon. In the process, they isolate the highly radioactive element radium. They found that radioactive materials produce intense waves, which they call alpha, beta, and gamma. Several types of radiation that they found were able to penetrate various materials and all of them could cause damage. All radioactivity researchers at that time suffered burns due to radiation, which is similar to burns due to sunlight, and only a few thought about it. This new phenomenon regarding radioactivity is known since the existence of patents in the medical world involving radioactiv material. Slowly, it is known that the radiation produced by the decay of radioactive material is ionizing radiation. Many radioactive material researchers in the past died of cancer due to the exposure they received from radioactiv material. As the understanding of nuclear progresses, understanding of the characteristics or nature of radioactivity becomes better. Some large atomic nuclei tend to be unstable, so decay occurs until a stable nucleus is formed. Understanding the three forms of radiation discovered by Becquerel and Curie is also getting better, alpha decay occurs when the nucleus of an atom releases alpha particles, namely two protons and two neutrons, equivalent to the nucleus of a helium atom; Beta decay occurs when the release of beta particles, ie high-energy electrons; gamma decay is the release of gamma rays, gamma decay is not the same as alpha and beta radiation, but it is an electromagnetic radiation with a very high frequency and energy. All three types of radiation occur naturally, and gamma ray radiation is the most dangerous and difficult to resist. Nuclear Reaction Fission Nuclear Reaction Fission is the process of splitting the nucleus into smaller atoms and is accompanied by the release of energy and neutrons. If this neutron is captured by another unstable atomic nucleus, then the nucleus will also divide, triggering a chain reaction. If the average number of neutrons released per nucleus fissioning to the nucleus of another atom is symbolized by k, then a k value greater than 1 indicates that the fission reaction releases more neutrons than the amount absorbed, so it can be said that this reaction can stand alone. The minimum mass of a fission material that is capable of carrying out independent fission chain reactions is called a critical mass. When neutrons are captured by the right nucleus, fission will occur immediately, or the nucleus will be in an unstable condition for a short time. When it was discovered during World War II, this triggered several countries to start research programs on the possibility of making atomic bombs, a weapon that uses fission reactions to produce enormous energy, far exceeding chemical explosives (TNT, etc.). The Manhattan project, run by the United States with the assistance of the British and Canadians, developed fission weapons used against Japan in 1945. During the project, the first fission reactor was developed, although initially it was used only for making weapons and not to generate electricity for the community. However, if the neutrons used in fission reactions can be controlled, for example with neutron absorbing material, and the conditions still make the mass of nuclear material critical, then the fission reaction can be controlled. This is what underlies the working principle of nuclear reactors. Neutrons move at very high speeds, to control the neutro from reacting with other nuclei, the neutrons must be slowed down by using neutron absorbing material before they can be easily captured. Nowadays, this method is commonly used to produce electricity. Fusion Nuclear Reaction If two atomic nuclei collide, there is a possibility of a fusion nuclear reaction. This process will release or absorb energy. If the collided nuclei are lighter than iron, in general the fusion nuclear reaction will release energy, but if the collided nuclei are heavier than iron, in general the fusion nuclear reaction will absorb energy. The most frequent process of nuclear fusion reactions
happens is in stars, the fusion nuclear reaction energy that occurs in stars is produced from hydrogen fusion nuclear reactions and produces helium. From nuclear fusion reactions, stars also form light elements such as lithium and calcium through stellar nucleosynthesis. This natural process of astrophysics is not an example of nuclear technology. Because of the high energy thrust of the atomic nucleus, fusion is difficult to do in a controlled state (eg hydrogen bomb). Controlled fusion can be done in particle accelerators, which is a system of how synthetic elements are made. Technical and theoretical difficulties hinder the development of nuclear fusion technology for civilian use, although research on this technology throughout the world continues today. Nuclear fusion theoretically began to be investigated during World War II, when Manhattan Project researchers led by Edward Teller examined it as a method of making bombs. The project was abandoned after concluding that this required a fission reaction to activate the hydrogen bomb. This continued until 1952, the first hydrogen bomb explosion was carried out. It is called the hydrogen bomb because it utilizes the reaction between deuterium and tritium, an isotope of hydrogen. Fusion reactions produce more energy per unit mass of material than fission reactions, but are more difficult to make them react in chains.
Nuclear technology for military purposes.
Given that nuclear technology is a very strategic advanced technology, since the second world war, weapons of mass destruction based on nuclear technology have been developed, known as nuclear weapons and nuclear technology-based warfare equipment, one of which is when nuclear dive.
Nuclear weapons are one of the tools of mass destruction that get explosive power (nuclear power) from nuclear reactions, both fission reactions or a combination of fission and fusion. Both release large amounts of energy from a small mass, even mini nuclear weapons can destroy a city with explosions, fire and radiation. Since the end of the second world war, international bodies such as the United Nations, in this case specifically handled by the IAEA, have sought to control the use and development of nuclear technology as a weapon of mass destruction. In the Second World War, America financed a secret project called the Manhattan Project, this project had the aim of making nuclear weapons based on each type of fissile material. In implementing the project, on July 16, 1945 the United States detonated the first nuclear weapon in an experiment codenamed “Trinity”, which was detonated near Alamogordo, New Mexico. This experiment aims to test how to detonate nuclear weapons. Out of the interests of the pilot project, the first uranium bomb, named Little Boy, was detonated in the city of Hiroshima, Japan, on August 6, 1945, followed by the detonation of the Fat Man plutonium bomb on Nagasaki. Since the explosion of Fat Man, Japan has its knees in the allies and the end of the Second World War. Since the explosion, no nuclear weapons have been released offensively. However, the arms race to develop weapons of destruction occurred. Four years later, on August 29, 1949, the Soviet Union blew up its first nuclear fission weapon. The British followed on October 2, 1952, France on February 13, 1960, and China on October 16, 1964. With weapons of conventional destruction, nuclear weapons still had a lethal effect until 2-5 years after being detonated in addition to the victims who died shortly after being detonated. Half of the victims killed on Hiroshima and Nagasaki died two five years after a nuclear explosion caused by radiation exposure. Besides nuclear weapons, other weapons of mass destruction based on nuclear technology are radiological weapons. Radiological weapons are a type of nuclear weapon designed to spread dangerous nuclear material into enemy territory. Weapons do not have explosive capabilities such as fission or fusion bombs, but contaminate large amounts of territory to kill large numbers of people. Radiological weapons were never released because they were deemed useless for conventional armed forces. But this type of weapon raises concerns about nuclear terrorism. From 1945 to 1963, more than 2000 nuclear experiments were carried out. In 1963, all possession countries and several non-nuclear weapons states signed the Limited Test Ban Treaty, which stated that they would not conduct nuclear weapons testing in the atmosphere, underwater or in space. This agreement still allows underground nuclear testing. France continued nuclear experiments in the atmosphere until 1974, China until 1980. The last underground experiment by the United States was carried out
in 1992, the Soviet Union in 1990, and Britain in 1991, while France and China were until 1996. After adopting the Comprehensive Test Ban Treaty in 1996, the whole country was sworn to stop all nuclear tests. India and Pakistan which were not included in these countries conducted their last nuclear test in 1998. Nuclear weapons are the most deadly weapons ever known. During the Cold War, two major powers had a large amount of nuclear weapons that were enough to destroy hundreds of millions of people. Generations of humans live in the shadow of nuclear destruction, reflected in films such as Dr. Strangelove and Atomic Cafe.
Nuclear Submarine (KSN) is a submarine that operates using nuclear power as a power source. KSN uses a pressurized water reactor as a source of power to rotate the main turbine that drives the propeller and electric motor battery charger that produces electricity for various purposes. In contrast to diesel submarines, nuclear submarines do not need to come to the surface to suck air as diesel submarines do that require air to burn fuel. The superiority of the KSN lies in its operational period and is more powerful although the submarine has a large size and must be in diving conditions, uranium as fuel from the reactor can be replaced after 3 years of use. The operational hindrance factor for nuclear submarines is the logistical needs or supply of the crew. The first KSN was made in 1951, spearheaded by a United States Navy officer, Kapt. Hyman G. Rickover. His first work was: USS Nautilus (1951) The revolutionary of the KSN was the use of nuclear reactors to generate propeller motors and recharge batteries which would be used by electric motors. So the position of the diesel engine was taken over by the Mini Nuclear Reactor. While the electric motor is maintained. The advantage of using nuclear power is huge. • First, nuclear power systems (uranium atom fusion reactions) no longer require air circulation. Can be done under water. Thus KSN no longer needs to surface. A KSN can travel the world within 2 months without appearing. • Second, saving fuel (uranium). KSN does not need to refuel for a long time. American KSN can operate for 25 years without fuel replacement. At least the components that require replacement are batteries (batteries) that are already weak or damaged. How it works: In principle, in the operation of the KSN there is no longer a procedure to divert the generator from a diesel engine to an electric engine as applicable to Conventional Submarines (KSK). However, the principle of KSN’s rise-and-sink work is still the same as Conventional Submarines, namely the mechanism of ballast tank filling and emptying. This principle was first made by Robert Fulton (1805).