Nuclear fission energy released

The energy from nuclear fission is released mainly as kinetic energy of the new, smaller nuclei and neutrons that are produced. This kinetic energy is essentially heat, which is used to boil water to generate steam that turns turbines to drive electrical generators. In a nuclear power plant, the electrical generation area is essentially the same as in a plant that burns fossil fuels to boil the water. 

In the United States, however, the public perception of nuclear energy is less than favorable. There are formidable disadvantages, including the creation of radioactive wastes and the possibility of an accident that releases radioactive substances into the environment. In rebuttal, advocates point out that we cannot insist that nuclear fission energy be absolutely safe while at the same time accept tanker spills, global warming, acid rain, and coal-miner diseases. 

Nuclear Explosions Although conventional explosives have become the weapons of choice of terrorist groups, a joint report issued in 2008 by Harvard s Kennedy School of Government and the Nuclear Threat Initiative reminds us that there is a real danger that terrorists could get and use a nuclear weapon.16 In order to understand what this would mean, we return to the atomic nucleus. A nuclear fission reaction releases far more energy than any ordinary chemical process. The Oklahoma City bomb was equivalent to the explosion of approximately 40001b of TNT.17 In contrast, the atomic bomb dropped on... 

Safety trials were conducted to investigate the behaviour of the core of a nuclear device under simulated faulty detonation conditions. The core is destroyed by the conventional explosive detonation of such a device, with the production of finely divided plutonium and plutonium oxide which are widely dispersed if the test is not confined. Usually no fission takes place, though there was a very small fission energy release in three of the French underground safety trials. (Since there was some explosive yield, these three trials are sometimes counted as nuclear tests which would put the total number of underground nuclear tests at Mururoa and Fangataufa atolls at 140 rather than 137.) All of the 15 safety trials were carried out at Mururoa. 

Nuclear fission reactions release a lot of energy. Where does the energy come from Well, if you make very accurate measurements of the masses of all the atoms and subatomic particles you start with and all the atoms and subatomic pcirticles you end up with, you find that some mass is missing. Matter disappectfs during the nuclear reaction. This loss of matter is called the mass defect. The missing matter is converted into energy. 

Wlieii very heavy nuclei, such as those of uranium and plutonium, are split into lighter nuclei having less total mass than the very heavy nuclei, energy is released. The process is called nuclear fission. In either nuclear fission or nuclear fusion, much of the convened rest energy emerges as kinetic energy, heat, and light. 

Frisch then demonstrated in his laboratory the tremendous release of energy accompanying fission, and a short paper by Meitner and Frisch in the British journal Natnrcin 1939 revealed the moinelitous concept of nuclear fission to the scientific world. It provided a new source of energy for the Earth, while at the same time introducing the possibility of a new weapon capable of tinbelicr able destructive power. 

Nuclear fission is a process in which a heavy nucleus—usually one with a nucleon number of two hundred or more—separates into two nuclei. Usually the division liberates neutrons and electromagnetic radiation and releases a substantial amount of energy. The discoveiyi of nuclear fission is credited to Otto I lahn and Fritz Strassman. In the process of bombarding uranium with neutrons in the late 1930s, they detected several nuclear products of significantly smaller mass than uranium, one of which was identified as Ba. The theorectical underpinnings that exist to this day for nuclear fission were proposed by Lise Meitner and Otto Frisch. Shortly after Hahn and Strassman s discovery. 

The process of nuclear fission was discovered more than half a century ago in 1938 by Lise Meitner (1878-1968) and Otto Hahn (1879-1968) in Germany. With the outbreak of World War II a year later, interest focused on the enormous amount of energy released in the process. At Los Alamos, in the mountains of New Mexico, a group of scientists led by J. Robert Oppenheimer (1904-1967) worked feverishly to produce the fission, or atomic, bomb. Many of the members of this group were exiles from Nazi Germany. They were spurred on by the fear that Hitler would obtain the bomb first Their work led to the explosion of the first atomic bomb in the New Mexico desert at 5 30 a.m. on July 16,1945. Less than a month later (August 6,1945), the world learned of this new weapon when another bomb was exploded... 

A nuclear fission explosion. Such a dramatic and destructive release of energy had never been seen before the development of the "atomic bomb" during World War II. 

The two nuclei on the right side are just two of the many possible products of the fission process. Since more than one neutron is released in each process, the fission reaction is a self-propagating, or chain reaction. Neutrons released by one fission event may induce other fissions. When fission reactions are run under controlled conditions in a nuclear reactor, the energy released by... 

The heart of the nuclear reactor boiler plant system is the reactor core, in which the nuclear fission process takes place. Nuclear fission is the splitting of a nucleus into two or more separate nuclei. Fission is usually by neutron particle bombardment and is accompanied by the release of a very large amount of energy, plus additional neutrons, other particles, and radioactive material. The generation of new neutrons during fission makes possible a chain reaction process and the subsequent... 

Nuclear installations are provided with a pressure explosion suppression and containment shell as an accommodation system against any sudden energy release resulting from an uncontrolled nuclear fission reaction. The internal air pressure is maintained at a level lower than the external atmosphere. 

STRATEGY If we know the mass loss, we can find the energy released by using Einstein s equation. Therefore, we must calculate the total mass of the particles on each side of the nuclear equation, take the difference, and substitute the mass difference into Eq. 6. Then we determine the number of nuclei in the sample from N = m(sample)/m(atom) and, finally, multiply the energy released from the fission of one nucleus bv that number to find the energy released by the sample. 

A nuclear bomb is a terrifying example of the enormous amount of energy released by nuclear fission. A bomb, however, is not the only way to extract the energy produced by nuclear fission. Instead, nuclear fission can be used... 

Schematic view of a nuclear power plant. The energy source is the core, in which a fission reaction occurs. The rest of the plant is designed to transfer the energy released during fission and convert it into electricity.

Understanding fusion invites another question If fusing nuclei releases energy, how did the early atomic bombs work In those bombs, nuclei were not fused, they were broken apart by nuclear fission. So, where does the energy of atomic bombs come from An important piece of the answer came from a brilliant Jewish scientist who fled Nazi Germany shortly before World War II. 

The process of radioactive decay (also known as radioactivity) involves the ejection from a nucleus of one or more nuclear particles and ionizing radiation. Nuclear fission is a reaction in which the nucleus splits into smaller nuclei, with the simultaneous release of energy. Most radioisotopes undergo radioactive decay processes and are converted into different smaller atoms. 

Since about 1940, mankind has realised that energy could be released if the very light nuclei of hydrogen could be made to react to produce deuterium or helium, where nuclear fusion would provide energy. The alternative is nuclear fission of the very heavy elements to give two nuclei of lower atomic number. Already there exist many nuclear power stations using fission but none using fusion. We return to the discussion of the potential value of nuclear power in Chapters 10 and 11. 

Nuclear fission is the breakdown of a nucleus into two or more smaller nuclei with the release of energy. The most useful fission process involves the decay of U-235 when hit by a neutron ... 

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