nuclear reactor

Examples of nuclear reactor in the following topics:

• Nuclear Fission in Reactors

  • Nuclear reactors convert the thermal energy released from nuclear fission into electricity.
  • Just as conventional power stations generate electricity by harnessing the thermal energy released from burning fossil fuels, the thermal energy released from nuclear fission can be converted in electricity by nuclear reactors.
  • Nuclear reactors generally have automatic and manual systems to shut the fission reaction down if unsafe conditions are detected.
  • A nuclear reactor coolant -- usually water, but sometimes a gas, liquid metal, or molten salt -- is circulated past the reactor core to absorb the heat that it generates.
  • The nuclear power industry has improved the safety and performance of reactors and has proposed new safer (but generally untested) reactor designs.

• Gamma Rays

  • Some rare terrestrial natural sources that produce gamma rays that are not of a nuclear origin, are lightning strikes and terrestrial gamma-ray flashes, which produce high energy emissions from natural high-energy voltages.
  • Notable artificial sources of gamma rays include fission such as occurs in nuclear reactors, and high energy physics experiments, such as neutral pion decay and nuclear fusion.
  • Gamma radiation from radioactive materials is used in nuclear medicine.

• Thermal Stresses

  • (Pyrex® is less susceptible because of its small coefficient of thermal expansion. ) Nuclear reactor pressure vessels are threatened by overly rapid cooling, and although none have failed, several have been cooled faster than considered desirable.

• Nuclear Fusion

  • In nuclear fusion two or more atomic nuclei collide at very high speed and join, forming a new nucleus.
  • Nuclear fusion is a nuclear reaction in which two or more atomic nuclei collide at very high speed and join to form a new type of atomic nucleus.
  • Researchers are working on a reactor that theoretically will deliver 10 times more fusion energy than the amount needed to heat up plasma to required temperatures.
  • Workable designs of this reactor were originally scheduled to be operational in 2018; however, this has been delayed, and a new date has not been released.
  • Analyze possibility of the use of nuclear fusion for the production of electricity.

• Nuclear Size and Density

  • Nuclear size is defined by nuclear radius; nuclear density can be calculated from nuclear size.
  • Nuclear size is defined by nuclear radius, also called rms charge radius.
  • It can be measured by the scattering of electrons by the nucleus and also inferred from the effects of finite nuclear size on electron energy levels as measured in atomic spectra.
  • Nuclear density is the density of the nucleus of an atom, averaging about $4 \cdot 10^{17} \text{kg/}\text{m}^3$.
  • The nuclear density for a typical nucleus can be approximately calculated from the size of the nucleus:

• Binding Energy and Nuclear Forces

  • Nuclear force is the force that is responsible for binding of protons and neutrons into atomic nuclei.
  • The nuclear force is the force between two or more component parts of an atomic nuclei.
  • Nuclear force is responsible for the binding of protons and neutrons into atomic nuclei.
  • Binding energy is the energy used in nuclear power plants and nuclear weapons.
  • These nuclear forces are very weak compared to direct gluon forces ("color forces" or "strong forces") inside nucleons, and the nuclear forces extend over only a few nuclear diameters, falling exponentially with distance.

• Nuclear Weapons

  • A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions—either fission, fusion, or a combination.
  • A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion.
  • Only two nuclear weapons have been used in the course of warfare, both by the United States near the end of World War II.
  • In addition, it is also widely believed that Israel possesses nuclear weapons (though they have not admitted to it).
  • The first nuclear weapons were gravity bombs, such as this "Fat Man" weapon dropped on Nagasaki, Japan.

• Conservation of Nucleon Number and Other Laws

  • Through radioactive decay, nuclear fusion and nuclear fission, the number of nucleons (sum of protons and neutrons) is always held constant.
  • In physics and chemistry there are many conservation laws—among them, the Law of Conservation of Nucleon Number, which states that the total number of nucleons (nuclear particles, specifically protons and neutrons) cannot change by any nuclear reaction.
  • Chain reactions of nuclear fission release a tremendous amount of energy, but follow the Law of Conservation of Nucleon Number.
  • Finally, nuclear fusion follows the Law of Conservation of Nucleon Number.
  • It is well understood that the tremendous amounts of energy released by nuclear fission and fusion can be attributed to the conversion of mass to energy.

• Other Forms of Energy

  • Thermal, chemical, electric, radiant, nuclear, magnetic, elastic, sound, mechanical, luminous, and mass are forms that energy can exist in.
  • Nuclear Energy: This type of energy is liberated during the nuclear reactions of fusion and fission.
  • Examples of things that utilize nuclear energy include nuclear power plants and nuclear weapons.
  • For example, mass is converted into energy when a nuclear bomb explodes .

• Gamma Decay

  • Emission of a gamma ray from an excited nuclear state typically requires only $10^{-12}$ seconds: it is nearly instantaneous.
  • Gamma decay from excited states may also follow nuclear reactions such as neutron capture, nuclear fission, or nuclear fusion.
  • Such nuclei have half-lives that are easily measurable; these are termed nuclear isomers.
  • Some nuclear isomers are able to stay in their excited state for minutes, hours, or days, or occasionally far longer, before emitting a gamma ray.
  • Explain relationship between gamma decay and other forms of nuclear decay.